Emotional Overload

Being in a state of grief causes you to overreact to things that you would normally just accept as a way of life. To name a few...
1. Missing events with friends
2. A slight change in plans that you only had planned in your head
3. Your friends from High School having new friends

I'm having the most trouble with 3 right now. My best friend from High School has replaced me. This sort of thing should be expected, but it's heartbreaking seeing things we did done with someone else. I just always thought we'd be around...but we're not. They haven't been there for me, and I haven't been there for them. It's slowly eating away at me.