Sex Issue

Hi,

I have been married for more than two years now. Me and my husband share a very good relationship. We are very understanding and I always feel like being around him always. Everything is superb. Only the issue is regarding sex life. I enjoy the foreplay but during insertion I really feel scared. He really loves to have sex at least twice a week but I always refuse. I never get that mood to do it. We have done many times and I never got orgasm. Now the penetration is also happening a little but it hurts. I'm really worried. He is very understanding and never let this issue effect our sex life. But what can I do to increase my sex desire? I have got checked up with doctor by injecting some machine and everything inside is pretty normal. No problem health wise.

Please let me know your advices