Selfish

My husband and I have been ttc for over 3 years.  We had a miscarriage in November of 2013 when I was 5 weeks along.  After two fertility specialists they have told me I have pcos.  My husband is 32 and I am 24.  I am no stranger to the fact that my husband has been around the block a time of two. He wasn't very smart in his younger days and has some prior children and we're not 100% sure how many.  I have yet to meet his youngest son because of distance issues. However this weekend we are going to see him for his birthday.  I am very happy for my husband to be amble to start seeing his son again but at the same time I am dying inside alittle because of a few things. I hate the fact that other women have had my husbands children and I don't seem to be able to and my husband seems to be able to have then and I'm broken.  I have been trying to figure out if I am a bad person because of this. I see my sister with her daughter and I am insanely jealous. I love them both but I always find myself asking why her and not me. My neice was an opps. Why can't I have my miracle.  Does these thoughts make me a bad person? I'm sorry for ranting but I just have no one else to turn too anymore. My husband is always telling me someday we will have a baby, my mother tells me someday it will happen. But sometimes I just want to scream!