Hi and welcome.
I was first dx'd major depressive episode, then major depression and in March BP II. Tried a mood stabiliser (sodium valporate) which didn't help.
Only today got put onto Lamictin, and will work my way to 100mg. Then possibly add an anti-dep.
I tihnk it's quite necessary to only change one med at a time, to be able to know which one is working/causing grief.

Don't stress too much about the dx. You are not alone. We all learn all the time from each other and offer great support. Having a dx makes it much easier to understand yourself and you can get help.

Hoping I don't get suicidal on the Lamictin....!!! I was bad enough without it, and this is supposed to pick me up! I mainly battle with depression, with some minor hypomanic episodes