Seriously, what is wrong with me?

I'm getting to the point where I'm just straight up getting annoyed with myself. I have been really sad, moody, and irritable for going on 2 years. Whenever I'm happy and one little thing doesn't go right, I go into this deep sadness that I can't really explain. Sometimes I feel like I have anxiety to the point where I'm on a verge of a panic attack. One time I woke up from a nap and had a dream that I had to do a 200 page paper and I woke up almost in tears and had so much anxiety. I'm only 17 and I have had to go through many difficult things in my life. I have finally found a guy that I have very strong feelings for but I feel like what has been going on with me mentally is going to ruin it. PLEASE, someone, what is wrong with me?