<human>: Summarize the given text in a few sentences.

I have absolutely no idea why this happens. I've been like this as long as I can remember. 

I can remember couple of Christmases (is that even a word?) where everyone in my family was having a good time, while I was sitting somewhere alone, feeling really sad and like noone cares about me for no reason at all. I was sabotaging my own happiness by imagining that noone cares about me, that they don't even need me to be happy and look! I could stay here forever and noone would even ask me what's wrong (and if they did ask, I wouldn't answer, I'd just sit there looking angry).

Something similar happens now in my relationship. Right now my BF is having the best time of his life. Only last year he was battling depression and panic attacks, but now he's doing a course he likes, is constantly in contact with really nice and supportive people, got the best internship placement between everyone in his class and is just feeling better than ever. Except one thing... When he comes home, he constantly hears nagging about little things, how we don't spend enough time together anymore (he's quite busy and tired when he's not), how I don't feel supported and whatnot. It's crazy and I understand that, but I have no idea what to do to stop it, because I don't even know why is this happening. It's almost like I feel jealous of everyone who enjoys their life so I have to do something to ruin it.

If anyone has any idea what this might be, please, help. I don't want him to even think about leaving me because of this stupid behaviour.
<bot>: I tend to ruin any happy moments one might have for an unknown reason. Am looking for reasons why this might be happening.