XpzXp

I am 15 years old and now in the middle of high school, in the last couple of years I had a lot of ups and downs but now I feel very happy where I am mostly. I try to improve myself if it is by picking up girls or working out, but the thing is that for a while now I can't really be happy. By that I mean that I don't laugh and if I am laughing it is just a gigle and not really a laugh usually the only thing that I can't do is smile and all of that is beacuse I can't. I am usually a really happy guy, till a few months I would laugh to a point that I can't breathe just because I saw someone farting, sos what exactly happend to me? I had a period of time which I was depreesed because I was always thinking of the past and I was really sad that I didn't got to do something that I thought that I wouldve done by now. But I already appease with it. I don't know why but as I said I can't laugh and I barely smile and I don't know why, I read somewhere here that there is something called Dysthymia that might explain what I am going through. If it really is the case than what can I do? Should I go to a therapist? Should I take pils? And how can I treat this godamn thing? Because I wanna be happy, I wanna laugh again and be happy as I used to.