I can't have sex with my boyfriend

Saskia
So for the past couple of months I've been back and to to the doctors and on various courses of antibiotics for a water infection, bacterial vaginosis, thrush and I've had urine tests and a swab tests. All have come back clear but I can't have sex with my boyfriend. The pain I get when my boyfriend enters me at first is agonising and then it goes away but it's really put me off having sex with him and then afterwards I keep getting really strong abdominal pain. I've had STI tests and everything is clear and I'm just sick of being told there's nothing wrong because at the end of the day I know my own body. Any suggestions? Somebody PLEASE help