When I have intercourse with my wife and I first enter her vagina I feel a something sharp on her left side of her vagina and it causes my penis to be cut and swollen. It hurts during intercourse and when we are done my penis is swollen and usually cut under the head. What could be causing this?

I have no idea. I would shine a light in her vagina and explore with your hand.
All I can think of are: old tampon, old IUD falling out and caught, prolapsed intestine, even piece of bone protruding. But none of those feel right to me. Maybe she has a growth that is irritating enough when rubbing that it cuts you.