<human>: Give me a shortened version of the text

So my girlfriend (we'll call her Katniss) and I met this time last year. She's smart, kind, sweet, the perfect girlfriend. I love her and she loves me. 

But as with all relationships, friction happens. So Katniss has had chronic pain since she was little. Her mother has fibromyalgia, therefore we are certain that she has it too. In addition to pain, fibromyalgia can cause depression and anxiety, both of which she suffers from. 

I'm always trying to do nice things for her, always thinking about her. I'm always trying to show my love, and not just tell her. But I also have a problem with sex, and let's just say that she has questioned whether she's just a booty-call or not. I take full responsibility for my actions and she always forgives me. But lately it's gotten a wee bit worse. She has been asking me why I love her. I state the usual reasons like "I love your sense of humour, how loving and kind you are.." etc. But that doesn't seem to be good enough for her. I suffer from depression and have problems identifying my emotions as it is, so when posed with this question it really baffled me. It was at that point that I realized, I don't really know _why_ I love her. I just know that I do. 

inb4 shitstorm. We usually have a very healthy relationship. Never fight, we always get along. So this is all so sudden and I just don't know how to cope.

I don't really know what to do. I'm not sure if this is just her anxiety/depression acting up, if I need a therapist to figure out my feelings, or something else.
<bot>: GF asks why I love her. Can't answer because I don't know why, I just know that I do.