We really can't tell you what is wrong over the internet. You have more than enough reason to see a gynecologist to determine what is causing your symptoms and if there is any reason why you haven't become pregnant.

There may be several issues here and the doctor will get as much information from you as possible and probably need some tests done before they can help.

You truly need to have the assistance of a good gynecologist to help try and successfully treat you. We have an excellent, friendly Depression site and if you need a place to talk, I guarantee you will find nice people there, who may have been where you are now. Also, the community leader at this site, Merely Me, is community leader on the depression site. She herself wrote an article about the Emotional Pain of Infertility, having gone through it. The article is an emotional read and may give you some solace and ideas. Try it.