I just need to vent..

I've been trying to get pregnant for months now & I feel like it's never going to happen. every time I think it will it just leads to disappointment. I don't know what else to do. we try every other day when I'm ovulating. for four months straight. it just seems so unfair. I know someone who got pregnant without even trying, then had the baby, got pregnant two more times didn't keep them, and now is pregnant again! I don't understand what I'm doing wrong here.. depression is kicking in slowly..