Who else feels like this?

I'm always seeing all of these lucky women and young girls with positive pregnancy tests and big pregnant bellies. Me and my husband have been trying for almost a year and still no luck. I'm just so jealous of all of the women who can get pregnant so easily. Sometimes I wonder if there's just something wrong with my body but my doctor told me many times that everything is fine but I just don't believe it. I've thought about just giving up on trying. Should I just give up or keep trying?