I Have Been Self Medicating My Bi Polar.. PTSD..with Meth

I have been self medicating my bi polar.. PTSD..with meth for years. I have a very hard time mentally trying to get off.. suicide thoughts..schz comes back quickly all too fast.. I just found out I have cancer and I need to get off meth but mentally I am not ready to go thru those extremely harsh moods by myself..any ways that are easier without telling any DR as they will label me a drug addict in my files and I will not get the healthcare I need as a cancer paktient..help!!