Will I ever be happy? That is the question on the mind of everyone who knows the hell of depression like you obviously do. Scary question, too.
I really have no intelligent data or input, but I have my own opinions with which I am quite impressed. I'm so smart, that, when others get irritated with me, it is simply because I am operating at a level of intellectual functioning that is far to intimidating to them.
All sarcasm aside. I think that like the stomach's purpose is to digest food and it makes itself noticed when it has had none for a while, the mind is the same. Only thing is that the mind, even life, digests "purpose." When it has no life purpose other than physical and sexual appetite satiation, then it (the mind) demands food. It's hungry. There are individuals who are happy leading lives only to satisfy body appetites. The world to them is like being in a big zoo. Just an animal. They are okay with it. Others' minds want more than that (like yours), so we are called mentally ill, because we want more than just satiated appetites. So our mind hurts. It needs purpose to keep it from being hungry. It needs to be well nourished on a daily basis. Just "being", simply isn't good enough. Relationships cover a lot of bases, and offer some purpose for living pretty well.
I believe that since I never asked to be born, there must be some other power that requested that I be born (this is simply my belief, nevertheless). That power must have some ideas about my life purpose. That's why I pray. Yes, I am better than everyone else. Shame on you! (I'm being sarcastic again!) Anyway, it often means relating, or helping others. I am not that spiritual technically because I desired a female relationship (in that relating to others scheme) in order to satisfy my sexual urges and provide social validation in the process. However, I have been truly happier since March of 2012 for the simple reason that I leaned on a group of peers for support and progressed to using the strength received from them to help others (very popular self help scheme). I take medications and meet individually with someone as well (of the same sex for talk therapy). If the girl who you are seeing wants to be friends that sucks. Heard that one. I'm an ugly guy, so that's to be expected. You have a purpose, a talent, like a gift to share, and that is where happiness is.
What is your talent? I think that takes introspection, some risk, and a lot of patience.