Complex sentence: His lyrics do not necessarily focus on the above mentioned negative aspects; they are simply explaining how hard it is to live with something like a drug addiction, his need for it, and unwillingness to go without it (e.g. Gimmie Heroin).
Split into simpler sentences: His lyrics do not necessarily focus on the above mentioned negative aspects. Some songs do not promote drug use; they are simply explaining how hard it is to live with something like a drug addiction, his need for it, and unwillingness to go without it (e.g. Gimmie Heroin).