Neptune square Sun

This indicates tendencies of psychologically based inhibitions, restrictions and frustrations which pose considerable challenges that need overcoming before the more positive characteristics of Neptune and the Sun emerge. 
You tend to lack confidence in your identity and ability to achieve your ambitions. Part of this may have been derived from your parental relationships, especially with the father, as your developing nature may have experienced conflict through lack of understanding or of perceived love; it may have been that by asserting your own individuality you clashed with the stronger parental will.The results are that your self-confidence has fragmented, and that your application of will is less focused and effective, and consequently you have developed psychological defences against others and from facnig personal failure. 
This is displayed in escapism, and avoidance of responsibilities and of the need for self-discipline, unless a powerful Saturn in your chart can rebalance this tendency. Preferring to run away from confronting reality leads to distorted perceptions, which make careful evaluation of options difficult as well as generating fears of making decisions which may prove to be unwise. At its worst, this can create inertia through fear of taking deliberate action. These inner images of failure tend to create external failures, and so emphasise a repetitive vicious circle. Yet by linking this pattern of failure within aims and ambitions that are probably beyond your current capabilities to achieve, you also succeed in evading the realisation that you are creating most failures in your life. This is exacerbated by the dreams of the unintegrated and unfulfilled Neptune, who may be noticed as a thread of guilt related to your lack of achievement, and as an ongoing sensation of discontent. Your solar power is being diverted and dissolved by the activity of an unintegrated Neptune, and, unless you can begin to reassert this solar centre and face your Neptunian challenges, this unsatisfactory condition may continue. 
These challenges can be mitigated by a decision to make sufficient effort to connect to your hidden solar centre, to move beyond those superimposed images of guilt, failure and inferiority that have developed as a defensive response to emotional pain. Such a reorientation may not be easy to make, as you will be opposing established patterns of behaviour, yet the gains that can be made are likely to transform your life. 
The first step is self-acceptance, to cease any self-judgement and condemnation. Then, if you really want it to happen, feel confident that any change can occur. You have sufficient inner creativity, imagination and potential waiting to be released from imprisonment, although finding appropriate channels of expression may still take a little longer. However, you need to define any ambitions within a more realistic perspective than previously. Possibly some form of counselling may be effective in helping you gain more clarity regarding your self-potential, or workshops in self-assertion and decision-making / goal-setting. In effect, you are being asked to see yourself as a young child, ready to enter adulthood, and you are expected to recreate yourself into a new and more suitable identity. Take smaller and easily achievable steps in this process of recreation; acknowledge that occasional failures are inevitable, but try not to turn them into traumatic dramas, and realise that success will not happen without the parallel risk of failure side by side. Everybody is a failure at something, and that isn't an excuse to condemn yourself again. 
As your self-confidence grows, your life will begin to take a more positive shape. It will not happen overnight, as transforming long-established behaviour patterns cannot be achieved that quickly; but persevere, anc changes can happen. Perhaps using techniques like creative visualisation and affirmations, or subliminal programming encoded on self-development cassette tapes, could strengthen this process. The essential realisation is that change is possible, and that you can achieve this in your own way; in hope lies the fountainhead of the waters of potential and transformation. Such improvements can benefit your intimate relationships too, as well as enhance your self-image, confidence and decision-making abilities. 
Generally you are emotionally vulnerable, possibly exploited or abused by others, deceived or manipulated in various ways; but if these tendencies exist, they are reflections of those dominating patterns within you. There can be unusual emotional needs and desires linked with romantic idealism that are expressed in physical sexuality; these may require healing and cleansing in some way. But the proposed transformation and refinement that is implied by resolving the conflict of the Sun and Neptune would simultaneously deal with that level too. 
There can be an attraction towards occultism and mysticism, which, if followed in the pre-transformation stage, can lead to self-exaltation (in contrast to an inferiority complex), and to becoming self-deluded as a voice of God or the Masters; although, if the transformation has been made, you could actually function in such a way as a purer channel. But some degree of caution and restraint may need making if you do explore such dimensions of life, as there can be an unconscious desire for self-aggrandisement operating through and motivating your actions. As the imagination aspect of Neptune is so strong, this can create inflated egotism and self-delusion where instead of finding the light you become lost in the dazzle of glamour and illusion.