Painful Sex

So this is a touchy subject for me. I'm 27. For the last year now, my boyfriend and I have barely been able to have sex. It hurts like hell for me. It truly feels as though I'm a virgin all over again. The only thing that has really changed in the past year is I became sober. I don't know if that has something to do with it or not. I've seen 2 doctors already. I'll be seeing my 3rd soon. The only answer I keep getting is that it's a yeast infection. I'm 100% positive that is not the reason this is happening. Is there anyone else who has experienced this or has any idea as to what could be causing this? I want to be able to be sexually intimate with my boyfriend again. PLEASE HELP!