Being unable to have a child is like having a choice involuntarily taken away from you. You have reason to be upset, but unless your doctor has told you you are infertile, don't get too upset yet.
I'll tell you a little story. nwlinkvxd's (my fiance if you didn't know) mother was expected to be infertile due to endometriosis (sic). It didn't help that nwlinkvxd's dad has a low sperm count as well. The doctors were 99.9% sure she could never have children. She and nwlinkvxd's father tried and tried and tried to get pregnant for several years (they married at age 16 and 18 respectively). Then, finally, his mother was starting to feel ill (as I remember the story) so she got tested for pregnancy...and sure enough! Despite all the odds, she was able to have a girl. And then four years later, she had nwlinkvxd!!! Thank god, because I get to spend the rest of my life with him!
So don't give up hope. And you know, like nickynicole says, you can always adopt (even if it's not the same to you) because you are helping one child understand what the meaning of love and true parents are.