Sorry to hear of your long struggles.
I was in a very similar situation to yours about six months ago. Treatment resistant and going hypomanic on ADs'. Then i switched Pdocs, he decided BP2, he put me on lithium right away to stabilize the moods.
Then we retried the AD and it went much better that time. It wasnt until then that i felt like the ADs were doing what theyre supposed to for me.
It took me a long time to understand that i had to cut off the highs with the lithium to prevent the deep lows