Hello concerned youngster, i have read your query and understand you are worried about your future sexual life i would recommend and strongly urge you to stop doing drugs for life.it would be hard ,but try your best to do the same. the risks and side effects outweigh the temporary pleasure and highs you get from the needle masturbation is a normal process that happens as you grow up as a part of exploring one s own sexuality.it is normal,just make sure that you are limiting the frequency and that it doesnt affect your personal and social life and academics/work.just dont over do it and try to avoid porn as it inverts the concept of sex far away from the reality. So my advise to you would be this: 1)stop drugs,avoid smoking and alcohol as all this causes infertility,inability to attain erections,causes premature ejaculations and may even cause cancers and can affect life and sexual life very badly. eat healthy,drink plenty of fluids,workout for half an hour to one hour daily which will improve stamina and testosterone levels in body. hope this helps and followup if you have further doubts.wish you have a fruitful life ahead.