Rolling a boulder up a hill

So it's been a little over two months since I lost my baby Jeremiah...
Time has eased the pain a little, but I feel very much alone in my
feelings. I started school hours away from my boyfriend and support
systems, where I knew No one just a week after my miscarriage. My
family still doesn't know I went through this miscarriage and I feel...
Isolated. My friend and boyfriend have some, but not a full understanding
Of how lost and inadequate I feel. I ran into my ex a few days ago, and
he told me his GF was 3mths along. Its infuriating. I was doing everything
I should, loved my Baby more than anything in the world, and I lost him.
Yet this guy, who is just now stopping his smoking habits, still drinks,
and has no real life goals can have his? I feel bitter, And I feel horrible
saying such mean things, because deep down I know he'll be a good father,
but I'm so jealous and angry and I want to know WHY did I lose my baby?
I don't think about people in those terms, and to add on, my mom just had
A baby, and as I held my baby sister I felt such loss. My mom and I have been
Arguing and not getting along, and I have no one. I'm trying to be strong.
Some days I feel strong and inspired, and I feel I can get through the day.
Others, I feel I need to wear a mask just so I don't fall apart. I feel like I'm
The one to blame... Like its my fault and I'm a horrible person... And I've
Been bashing my brains mentally just trying to understand and cope...
In isolating myself though, I have more time to think about it and when
You're alone... Pain crushes and destroys... Where do I begin to put back
these pieces?