I'm sorry you went through a tough time OP and it's great you are getting help and support and starting to see things more clearly. My partner also suffered/suffers with depression.
From my perspective It was awful to watch the person I love all but disappear on me. It broke my heart. It was very hard for me to stay strong, to get them the helped they needed (he couldn't see, what was so obvious to me) it knocked me down a long way, because I felt so rejected, and for me it was hard too, just in a different way and much harder for him I understand that. At times I didn't like him very much, I loved him with all my heart but at times I didn't like him very much.
The thing is, OP, like you, my DP was unwell you don't chastise unwell people in my mind you help them.
When he started to get help, I saw him come back to me. It was a difficult journey for us both, but I don't resent him, I've never resented him, I'm incredibly proud of him for getting help that was really hard for him to do.
Not everybody can do that.
If you think your partner was happier when you were unwell, then it's time to call it a day. As your well being is too important.
But, do you think maybe he struggled more than he can cope with? Or vocalise? Maybe he needs to talk to someone (that's not you) about how he feels too. It's very difficult being the loved one of someone with depression