It's nice having somebody there all the time, maybe that is why she is talking to you.
It's nice rubbing it in an ex's face that you are happy because it makes them jealous and want you more, further boosting her own ego. Which is working, you already admitted you are upset.
They don't want to see you happy without them when they see you
Further blocking her for a few months at this point in LC is still showing how you react to her and that she still affects your moods. Which is what she was trying to go for bragging about her new boyfriend.
Just textbook basics. I don't know how to work msn but I'm under the impression that you can't just remove them. Shame.
Keep in mind that while you feel this way now about her, you might not in the future. Don't assume so and don't assume you will want to in the future. People change all the time, the person she becomes might not be the person you want to be with. Don't get it stuck in your head that she is the one for you when you rarely talk to her.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.