Im rlly sorry all of this is happening, but I say first off:
LISTEN! So far the advice on here you have been given is the way to go..I was in deep depression for most of my life and I had one hall of a way getting through it [[I would chat about that another time, talking about the straight jacket and biting cops wont help you here]]
DONT CUT! What ever you do, thats what NOT to do...I reciently have done that, but I have my own special reasons why, but thats because I dont feel much pain but what I inflict on myself, and I dont mind the scars because I have my body pierced and tattooed, so I dont mind. but I dont incourage it in ANY cause.
DONT DRINK YOUR PROBLEMS AWAY!! My mother does that, and Ill tell you whatr my friend, it just makes matters worse [[same with drugs]]
Sports are indeed a good way to let out anger, but thats not always the only way to let it out, sometimes you just want to scream, and sometimes screaming is a great way or releaving stress. Sometimes I like to take a pillow to my bed and scream nice a long until Im out of breath, and then drink some water for my throat.
EAT! Dont eat like a pig, but just kinda munch a little here and there, if your not hungry, its understandable, in many cases like yours I would rather puke my stomach out than eat, but if your stomach is unsettled, drink something that is low in the pH level, nothing to acidy [[I find that it leads to getting really bad heart burn]]
Try reasoning with your boyfriend about things and agree to chill out, and talk to your mom..I have a feeling I know what it was she found, though Im not sure and I dont want to know..but try talking to her...I dont have the best advice as what to say because me and my mom arent really like daughter mother stature...we are more of the room mate relationship, so she and I dont really talk that much.
A lot of people may tell you to write down your feelings, but I dont recomend it because parents being snoopy [[you know no this]] will find it, and read it...and it wouldnt make anything better at all, so if you plan on writing your feelings out on paper, I suggest ripping it into many many many many little pieces of paper and flushing it town the toilet, its a specialty of mine [[except I fill a glass of water and make pulp xD]]
I hope things work out [[have worked out]] for you
Best Wishes - Nevermore