Why just why feeling so horrible right now

I've done everything right I got married and got my place and started trying for a baby and now my 18 year old baby sister got pregnant just bc she wanted I just lost a baby last month and started trying again she knows how hard everything has been for me yet its all she talks about and everything idk what to do I just feel like I'm a no good mess up anyone els feel this way or going threw the samething oh and on the other hand she hasn't even known her bf but for maybe 2 weeks