Miscarriage and friends

Well, I had a miscarriage a little over two weeks ago. I was almost 11 weeks. It devistated me and my fiancé, of course, but I had been doing pretty well with it up until today. Since I had my miscarriage, it has been very painful to see other people and their new babies. For example, a girl I'm friends with on fb had her baby 2 days after my miscarriage and I cannot bear to look at the pictures. 
However, my fiancé's best friend just found out he and his girlfriend (of less than 4 months) are expecting and I feel so hurt over this. I know it probably makes me queen bitch, but I feel so jealous. I do not mean to come across as harsh, but the two of them are self-professed "deadbeats." They smoke weed, drink regularly, and smoke packs of cigarettes all the time. Neither one of them can hold down a job, he's a college drop out and she doesn't even planning on going. 
I feel very upset because my fiancé and I have been very responsible. I did those things maybe once or twice in my whole life. I've always been able to hold a good job, and so had he. I addition, we've been together for more than 3 years. The two of us have constantly had to look after the two of them because they act so immature. We clean the house and cook, while they sit around watching movies and taking our food. 
Like I said, I feel like such a horrible person, but I am so jealous because I don't understand why I had to lose our baby, while they party 24/7 and they're fine. I did everything i could to be healthy and try to have a good pregnancy and it wasn't enough, and i still blame myself even though the doctor said it was not my fault at all. I hate feeling this way but I don't even know how to be around them anymore. I feel physically sick, I get so upset. Idk what to do.