Having an "FUIF" you really suck day

Today was a long day...work was busy, we were short staff and I got news that a co-worker is having twins. I'm honestly happy for her. She already has a 2 year old (in part thanx to clomid) and now she's having twins, after another round of it. So I'm happy for her. I just wished freaking clomid had work for me too, but instead the only time that I was on it I got a freaking big cyst that had to be aspirated (not a fun experience).
On the way home I checked facebook and the last 3 updates from my "friends" where:
1. A high school friend posted a pic of her 3day old newborn
2. My cousin thatjust seems like yesterday announced she was pregnant found out today she's having a boy
3. Said co-worker posted an ultrasound pic of her twins

After that I just kinda broke down...got home and just broke down crying by myself on the bed. It just seems so unfair that others seem to have it so easy. I know for my co-worker it wasn't that easy since she did have to do clomid. However, after trying clomid, femara for 4 cycles, and injections for other 4 cycles, a total of 5 failed IUI's I can't help thinking 1 or 2 cycles of clomid is easy. I'm not trying to be a bit**. I just feel like such a failure and empty. I guess the fact that I got an invitation for a baby shower 4 days ago, didn't help w/my breaking down and crying either.
Sometimes I wonder if I'll ever get to be a mom, sometimes I'm too scare to know the truth, I avoid thinking too much about it =(
Many times I feel alone on this, which is more depressing...
I also wonder if I'm/ have been such bad person and that's why I don't get to be a mother (some punishment) it's kinda stupid to think that, but it does cross my mind sometimes.
Like I said I feel empty and some days like today it's easier to feel that emptiness. Its like whatever temporary bandaid I put to cover the "wound" gets removed and it really hurts!