Eating Disorder

Hi, so I am not sure if this is the right area to post this but I just need some type of advice. I am 19 years old and I am in school heading towards nursing. I am extremely stressed out all the time, but over all I am pretty happy with my life. When I was 17 years old I was having trouble at home (parent drama) but long story short I lost a lot of weight, exercised constantly, starved and if I did eat I'd make sure my calorie intake was less than 300 a day, and it usually was a lot less. I am 5,4 and at that time i had gone down to around 117 which for me is rather thin. I knew I had a problem and I still do. But I have tried to control it and I have changed my life into a much better situation and I am a whole lot better with the disorder but I still struggle a lot with it and my self esteem. I actually still do use laxatives alot...which i know is a very big risk for alot of things, but I just can't stop. The really meaning of this message is that I am planning on going back on birth control ( i got off of it at 18 cause I had gained weight) .i have been dating my boyfriend for over 2 years now and I keep telling my boyfriend that I am going to go on the pill...but i keep putting it off because Im so scared it is going to make me gain weight again. I know that it's very stupid of me to rather risk pregnancy than gain weight but it is so hard for me. I know that the second I start to gain I am going to get depressed and I am going to get out of control again. I know that some pills have low estrogen and don't allow the body to retain as much water. I just, I dont know what to do. I am so scared that I'm going to gain weight and lose control of my life again. Has anyone ever felt like this...sorry if this is a stupid question...

-meg