Some of your emotions are caused by hormones and after a miscarriage your hormones are even more messed up and unbalanced than if you carried the baby to full term. In addition, it is NORMAL to be upset about this and sad.
Believe it or not the way your fianc�e is acting is also normal, for men. The male does not get pregnant, does not get the hormone boost during pregnancy, or become as connected to a baby inside of the mother even if she carries to the point of feeling the baby moving. Men typically feel more strongly about their partner than their baby, while women feel more strongly about the baby inside them, than their partner.
This is ALL NORMAL.
The best place for you to seek comfort is with other women who have gone through this, so you've come to the right place for that. Talking to your boyfriend will probably never solve anything or make you feel better because he just doesn't share the same feelings, and it's not his fault, it's just nature.
However, like most young men he needs to learn some patience and understanding and empathy.
I am so sorry for your loss. I have experienced two miscarriages in my life and it was a hard time but you do get through it, and you move past it, and you will be able to see other pregnant women, and babies and not burst into tears.
After two months you might want to go to your doctor, a low dose anti depressant taken temporarily might help a little. I didn't need them after my first, but I did after my second miscarriage. I am sure it was hormones because oddly I should have been more upset the first time, but I was not, the second time was a real bad time to be having a baby, but my hormones became so out of whack that I even experienced psychosis.
So, don't discount the affect of hormones!
Take care of you.