So beyond frustrated!

Heather • 💙Otto Wayne 9/7/18 💙💚Owen David 5/22/20💚
My husband and I have been TTC for about 8months now. A little back story- We have done everything in the "right" order (not that it matters if others havnt) we got engaged, bought a house, and I didn't move in until we were married. Before we got hitched we use protection and birth control because we didn't want to have kids out of wedlock. We have been married for about a year and a half and together 4years total. My mother in law is amazing and loves us very much but... I sometimes get the feeling that she loves her her nephew (our cousin) more than anyone. They are always going to concerts and events together and never invites us- not to mention that every time he makes a mistake she blows it off or makes it out to not be so bad.. She dosnt treat us bad by all means but he is "the golden child" and it's very annoying but I have learned to live with it and usually it dosnt bother me. 
However, we recently found out that he is going to be a FATHER!! His gf is very new, they havnt even been dating for as long as my husband and I have been ttc (of course they can get pregnant on accident and I can't even when trying!) no body really knows her and honestly isn't the biggest fan of her. She seems controlling in my opinion. I feel like this baby is going to be the "golden baby"..... The first baby from our generation....
Don't get me wrong I want the best for the child and I'm excited another family member will be joining our lives. But I feel hurt! My cousin gets everything! Usually having a child with someone you just met out of wedlock is a looked down upon thing, not for him! He gets a pat on the back..
I'm worried that if we ever do get pregnant it's just not going to be the same... Don't think badly of my mother in law though, because I can't write enough about how awesome she truly is.. But I'm jealous!!  And disappointed that he wasn't more careful, I mean they were on the verge of breaking up! 
I feel like this is going to be the grand baby she never had and I'm just sad... I don't know what to do or how to feel about this because it is not the child's fault but I feel like I'm always going to resent it..... :/ that's horrible to say I know...
I have talked to her in the past about how she treats us vs him but she just says that they have always been close and she just has higher standards for her son... Ugh whatever!