Pain and bleeding during sex

[mb123]

I am 19 years old and experience intense pain during sex. It is as if my vagina tightens up and almost rejects the idea of sex. It doesn't help that I know how painful it is going to be so I guess that my muscles tense up bracing themselves. Not only does it feel incredibly uncomfortable due to how to tight it is but it also feels like a sharp stabbing pain. I have also started bleeding after sex. It all started about 6 months ago when my periods randomly stopped. I got checked out at my gp because I was having symptoms of a pregnancy. After checking me out even my gp thought I was pregnant so made me do 2 tests from urine and even blood tests because she was finding it hard to believe that I wasn't pregnant. She saud I had a tilted uterus and that it was very swollen. My libido has pretty much gone. I'm not sure wether it's because I know sex is going to be painful, so I put myself off it, or wether it is something more serious. I have started to get really bad cramps really sharp the past few weeks. They come randomly and only last a few seconds but I am having them almost every day.