lesbian, divorced, and confused. please help.

Okay, helloooo everyone. Im hoping to get some kind of help here. So here goes. Im currently in a relationship with a great person, she has some flaws, like everyone, but for the last few months i have been questioning whether or not i want to be in this relationship or not, simply because i want to know why things didnt work out with my ex husband. I was married, to a guy, that at one point in time i was head over heels in love with, we met in basic training, and got engaged. I loved him as a friend and a lover, he was quirky a nerd and a very attractive and sweet guy made me laugh. I love him, even still after us being divorced for a year now. We got divorced for the same reason i think, because i started questioning my sexuality and he knew, that i was a lesbian when we married but didnt care, thats love. But i just wasnt happy after a few months. Maybe it was the miscarriage, i thought i was being punished for having thoughts of women all the time. But we separated and i went off to break up with my gf who i left for him bcz i thought it was the right thing to do. And i didnt want to hurt him, i was still questioning my sexuality and i didnt want him caught n the middle of it, i loved him too much for that, was i hone st with him about this no, and i regret that, so a year down the line ive had time to think and date and try and find myself, and find myself in the same prepredicament, in a relationship and questioning my sexuality. I miss my husband, i miss my best friend, and im not sure what to do, i have reached out to him and we have talked about where we stand. But my current gf is mentally ill and has been diagnosed with major depressive disorder and bipolar disorder pospossibly skitzo. So im not really sure what to do or how to handle this or anything. I mean she knows that im unhappy but she doesnt know why. I cant tell her bcz she will flip out and have one of her meltdowns and they gt violent. So im stuck, someone please help me .......