Absintence cause problems?

Hello- I am a 21 year old with a history of abuse. I really want a boyfriend and companionship and I would like to have but I absolutely do not ever ever ever ever want a kid. The doctors will not allow me to be sterilized because they say I am too young even though I made up my mind as a child that I did not want kids. I have not changed my mind since and will not yet. My carreer/education is my life. I also cannot afford to pump birth control hormones in my body because I was anorexic when I was 11-15 and it really messed up my body and I have polycystic ovary syndrome, and problems with weight etc, so I am very sensitive to hormone treatment. Although I knew if I was to have with just a condom, that wouldnt cut it. I DONT WANT TO RISK ANYthing.. Any advice? I have this fear that If I abstain from ( till I'm 40?) that I cannot keep a guy. I am not religious, I am not conservative, But I cannot ever have a kid. How can I have fun/ grow up without this over my head?