Neptune square Mars

The square aspect can pose a variety of inner tensions and compulsions that are difficult to acknowledge and integrate properly. It is indicative of the inner conflict and stress which often affects the nature of your relationships, especially emotionally and sexually. 
Most of your impulses arise from the unconscious mind, and so it can be difficult to perceive them correctly or to understand their nature. Squares involve frustration, and here both the energies of Mars and Neptune are mutually inhibiting, creating distortions in both their favoured ways of expression. Even the inner energy flow is distorted, with the Martian energy taking on an intermittent current, ranging from an obsessive urge for action (or release) to almost disappearing at times, leaving you with a minimum of motivation and vitality. Often the Neptune energy emerges in its distorted nature, in that there can be disconcerting emotional impulses, strange imaginations and obsessions, or negative types of habit=patterned behaviour, which can be essentially self-destructive through a vulnerability to the Neptunian addictions of drugs, alcohol and compulsive sexual obsessions. 
As there can be an inhibition in consistently and effectively expressing your self and your aims, this eventually creates a build-up of frustration, leading to internal pressures and stresses. This can form personality splits, where more negative aspects of the unintegrated unconscious mind erupt into the conscious personality and begin to dominate, almost as forms of possession. You can feel impelled to act in certain ways, and whilst you feel in a state of confusion, those hidden powerful motivations are directing your choices. 
There tends to be a 'vicious circle' in action, often due to that belligerent and aggressive way in which you can attempt to be self-assertive. Because of those unresolved inner conflicts, your style of emotional expression and your relationship with others are often tainted by vibrations of aggression which are registered and usually rejected by others. The result can be a rejection of your outstretched hand and of your aims. Yet as this becomes a repetitive pattern, your inner conflicts become more intensified, and so does part of your energy field which is sensed by perceptive people. Alienation can occur.
Because of inner blindness, you can fail to understand what is occurring, and thus enforce a developing pattern akin to paranoia, where you begin to imagine additional rejections by others, become extremely touchy regarding all social contacts and imagined slights, and then become defensively belligerent too as a form of protection. There is considerable self-deception happening, in that you fail to see the process within you. Through looking outwards, you fail to see the source of your difficulties. 
Sexual relationships can be a major battleground, and a central point for may of these tensions. The nature of your sex life and sexual desires is likely to be distorted to some degree. Sex and emotions are closely tied together, and it may be essential to achieve a redefinition through understanding. This may become the core of your obsessions and compulsive behaviour, stimulated by a highly active imagination. There is unease, anxiety and confusion related to your sexual impulse. This can arise from a lack of intimate opportunities, leaving the frustrated energy little option but to circle around within you, activating a variety of stresses and splits that ideally should be healed rather than widened. It could be that your imagination becomes over-active, creating unfulfilled sexual imagery and desires. or it may be aspects of your natural expressions of sexuality that you are refusing to acknowledge, and so repressing. It is certainly an area of inner contention. 
This often leads to an overshadowing guilt pattern developing, where you are attracted towards illicit affairs, or sexual activity which you believe is morally wrong. Resorting to unsatisfying sexual expression may be attempted, such as the purely physical release of the energy and pressures, as with prostitutes for example. This need for sexual release is a crucial one for you to come to terms with; it is essential to discover an approach which is fulfilling and which does not re-emphasize your inner conflicts. 
Relationship failures my be common until you begin a reorientation, a re-channelling of your energies into more suitable directions. You may find that your experience of the stresses inherent in this aspect is one of degree only, but much depends on the rest of the chart, and even then some degree of modification will still be required, especially if other aspects are challenging to Mars and Neptune. 
What is necessary is a confrontation with reality, where you assume self-responsibility for your situation and inner life. This is an acknowledgement of inner conflicts without feelings of guilt, denial or personal condemnation. Acceptance is the first step; this may be quite difficult to achieve, yet it is the first step towards a resolution of the problems and to allowing inner healing to occur. Stop mentally pointing at others and projecting any blame for your failures onto them; yet conversely, do not blame yourself either; just resolve to change things for the better in the future. Because experiences have led to the creation of repetitive patterns frustrating you, it does not mean that this situation has to persist. The potential is there for you to change it. Study the techniques of creative visualisation; take control over the areas in your life that you want to change or resolve. Begin to look for ways in which the energies of Mars and Neptune can be integrated together, where using your imagination creates bridges instead of more uncrossable abysses of neuroses, paranoias, illusions and obsessive sexual desires. Change your attitude to people; be willing to take a risk in re-creating your life. Instead of looking to take, look for where you can give, as this will redirect that Neptune energy into constructive channels, withdrawing it from the distortions of Martian energy and from overstimulating sexual desires. It is a sacrifice of an attitude that is necessary, and it is one that poses problems for you; in releasing it there lies the opportunity for a rebirth to occur. 
One key lies in the correct use of emotional and sexual energy, discovering a direction that can soak up its excessiveness and negativity, transforming it into a positive asset rather than a guilt-ridden obsession. Discover creative channels to pour it into; express it through the physicality of dance; through art, literature, music, drama. Even if the original creations are not beautiful or harmonious, be assure that over time their quality will change as your inner healing proceeds through the release of those frustrating poisons. Instead of being controlled by the energy, take control of it; plan and direct your life so that it moves in your chosen way. Eventually, with persistence, the pieces of the new jigsaw will fall into place and you will emerge into an experience of life that satisfies you. Fight those inner battles, and those conflicts can dissipate.