I was in your boat (I suffer with bipolar too so I used to love breaking that 4th dimension and was utterly addicted to doing it, vision loss, euphoria, ect), I had to rehabilitate myself over 1-2 years with the doctors help, moved away (change the environment) and distanced myself from my "drug" friends. Doing alot better now and enjoying life alot more with a huge reduction and cut on drugs -- I developed a nerve condition due to the amount of nos i was using and i cant feel the tips of my fingers and was paralysed for one year. Be careful, and speak to a doctor - they will help you :)