Well
I am sorry you went through all that **** and am glad you are getting out of that relationship. As far as how it affected you mental state I have been bipolar for a long time and have known many people who are and what you went through with your wife and all the stress related to that would most definitely be a trigger I mean in a big way. And I am glad you were able to get back on meds that helped you. I to am on Lamictal and it is a life saver for me the only thing that helps with the depression and that does not make me go manic.
I made the decision not my doctor in 2006 that I was one of those bipolars that can not take anti depressants. I have know for a lot of years that there are those bipolars who cant take anti depressants. And since I made that decisions in 2006 I have not had a bad manic episode since which is a big time record. Before 2006 I had not been on Lamictal for a lot of years but i knew that even though it is a mood stablalizer for some people it does have an anti depressant affect with out being an anti depressant. So I went back on it and it was the best decision for my mental health I ever made. But for me it takes a pretty high dose for it to do the job I take 450 mgs and hope to go up a little more to get rid of the very mild depression I am still having.

I wish you the best of luck in the path you have taken
good for you