I need help

So too start I haven't been fully diagnosed with endo because my doctor told me she can't diagnose me untill I become sexualy active. This was two years ago. Today I am 18 and just started having sex. My boyfriend of two years has been by my side the whole time. I got put on birth control to help with the pain I was having around and on my period. I still have constant horrible cramps. I get cramps all the time I feel like. The worse cramps are after sex. And the pain during sex is awful. For example if my boyfriend moves the wrong way even by a cm it hurts. Since I just started having sex a few months ago I haven't told anyone I'm sexually active.

I just need help because I don't know what todo. Thanks