what's wrong with me? Am I crazy?

I seriously don't know what's wrong with me, I feel like I'm going crazy. I keep lashing out on my own and hitting things till I hurt my self and I keep crying and having tantrums. I live alone and I've just turned 19. Could it be stress? I've always had to provide for my self from being small and I moved out just before I turned 18. I pay all my own bills, work for the most stressful company, I have no support around me. Dad and family live in another country, mum dosent seem bothered about me. Even though I still lend her Money ect, we just don't have that motherly daughter bond. You know, I feel like I have no support, noones proud of me, I feel like I'm alone apart from my bf. And I hate when I get In a sad mood because I become in a bad mood to him. Silly things will trigger me like my bf said he loves xmas and it made me upset because I'm always alone and my family have never done it like the others, we used to get 1 fake present and they used to all get drunk and that's it. No love at all. And tonight I was fine, started thinking about things and someone said something and I just started crying and smacking the wall. Please I don't want no one to judge me or think I'm going over the top but I don't know if it's normal or if I'm going through that time in life, but recently I've been all over the place with emotions . More when I'm on my own, in bed.