You most definitely do have & have had an eating disorder & it is getting worse so you have to decidse whether you want to live or die.
if you do nothing you will die!!

the chest pains could well be heart trouble or ulcer or just indigestion or muscle spasms from purging.
If you do not want to die then you & only you have to act & I mean now!!
1) go see a dr>>. Have full blood, urine tests done including oestrogen levels, liver & kidney function also have your blood pressure temperature & so on checked
2) referral to a dietitian.
3) referral to a counseelor/psychiatrist/eating disorder clinic
4) be prepared to put college on hold. It will still be there when you get better but won't be much use if you're dead!!!! This is not a joke, nor am I trying to scare you, just tell you the truth.
5) seek out an eating disorders support group.
6) tell your family & friends what you have been doing & are doing & how long it's been going on, they can help you, support & advise you. They may also need to find a support group to help them.
Good luck