Not your problem, his. He has decided to make choices not conducive to a partnership with you? I would leave/kick him out. The problem with blaming things on an illness is that no one holds a gun to the alcoholic's head, making them walk into the liquor store and buy alcohol and drink it. The same is true about his alleged bi-polar self and getting medical help for it rather than self-medicating and otherwise taking known illegal and harmful substances for his own purposes. At some point he has to self-destruct. I would not choose to be around when that happens. If you love him, give him a boundary ("Get off the roids and other self-medicating, find competent medical help and discontinue any relationship with younger woman or I'm/you're out of here") and follow through.