Hi there,
I think to confirm this is by being evaluated by a psychiatrist, if it has been, and your meds are still not stabilizing you, the pdoc should be made knowledgble, cause bipolars can have a special "acting" ability when they want their pdoc to think they are okay. My brother who is BP-I, use to do this often. I am bipolar-II (mild) and not really have had what would be a "manic" episode but more on the depressive end.
There is not much more I'd suggest but to talk to your pdoc, you may need an increase in the Lithium. I use to take a total of 900mgs of Lithobid, excellent stuff, but due to being more depressive than manic my doc had me decide to try Lamictal, and it has been very good, addressing the depressive side of BP-II.
If I should ever be where I was (5yrs ago)again then I would consider Lithobid again, was 1 3x a day (300mgs each) and I did fine with it.
I wish you lots of luck in getting some answer(s) and in following through with treatment.
It can be your drug use that is causing bipolar type behaviour too, I forgot to mention that in the begining of my reply, so I'd suggest you see a therapist besides a pdoc., help you get off the drugs, and tame your sexual escapades.
There is just so much we can all use our disorder for excuses, but we need to make the effort and take responsibility too.
Take care,
DE