I'm so sorry to hear what you are going through. I know it must be an incredibly difficult thing to experience. I'm not sure how long of a road this has been for you, but I know that it can be very challenging and painful.
Dh and I have been trying to conceive for almost 4 years now and have never had a pregnancy at all. We do have 2 wonderful adopted sons though. What I have learned through all this is that God really does have a plan for your life. From your post, it sounds like you are Christian. If that is the case, you can always cling to Romans 8:28 "And we know that in all things God works for the good of those who love Him, who have been called according to His purpose."
I know that is not some magic cure that will erase all of the hurt you are feeling, but it can provide comfort. Someday you will reach the point where you can look back and realize that yes, it hurt, but there was a reason. There are times where I look at my kids and thank God for our infertility and for using that to bring the boys into our lives. Of course, there are still times that it hurts as I would very much like to experience pregnancy and the birth of a child, but I know God is still working in my life.
Its okay (and good) to cry and scream and "throw a hissy fit" if you need to. You are right, it just flat isn't fair. Remember, God understands your pain and suffers with you because He loves you that much. There is a light at the end of the tunnel. I will keep you in my prayers.
Kristy