Most Helpful Girl
That's a really sh-tty way to go through a breakup, it would make anyone feel lousy. I don't know if this is going to make you feel better or worse, but I'm just gonna be honest. It sounds to me like she had her mind made up for awhile before the breakup, but was feeling bad or guilty about ending it even though that's what she really wanted... which she showed by acting angry and emotional all of the time. It's impossible to say if this new guy is a rebound, but I have a feeling that she knew him for a lot longer than 3 weeks.
Most importantly, I personally think that she handled the breakup really badly, and is still handling it badly by randomly contacting you and then blocking you. Maybe she's doing it because she still feels guilty, maybe because she misses having contact with you (you were together for 2 years, after all,) or maybe she's just self-absorbed and wants to keep you at an arm's length in case she changes her mind. No matter what her motive is, I think it's best for you to try to let it all go and move on - don't respond to her attempts to contact you and block HER from your life. Spend your time doing stuff that makes YOU happy and get yourself around people who are nice and appreciate you, and pretty soon you won't care at all why she's behaving this way.