Fed up of life

Hi everyone. I am desperately looking for advice, I am in a life crisis. I am a 2nd year nursing student, still only young (20yrs) , but i am desperately unhappy in my life. I suffer from depression, and have thought about finishing my life more than once. Let me tell you a bit more about me.
I come for an unsteady family, both my father and mother do not get on well together..we have been physically and mentally abused both since a young age, and this, has seriously affected my self esteem. I come from a good looking family, and have always got attention from boys because of my looks. But it never goes beyond a merse acknowledgment of looks. I am socially awkward, and have never had real friends. I got bullied in secondary school, and this still catching up on me. I fall for guys too easily, and end up absolutely crushed and heartbroken. I cry all the time, and am so unhappy in my life that i often feel like im looking at my life, and watching this stranger living it for me. I gain weight, I lose weight, its a constant battle, and worse more, i am living a life of fakeness. U grew up in a house where i had to watch my mam and da acting fake in front of people, pretending to be all nice and friendly, when the real truth was that they were the most unhappiest people you can imagine, both also suffering from depression. I dont know what to do anymore, because quite frankly I am so tired from it all. Just recently, i had lost a load of weight and was so happy with how far id come, i fell for a guy in my class, had never even spoketo him, but started obsessing over him , because he used to stare at me all the time. End up sleeping with him one night, a few weeks later hes going out wigth a girl in my class. The result of this?? Back to overeating, no motivation, crying, tearfulness.. I cant live my life like this anymore.