Does he really like this new girl?

Recently me and my boyfriend broke up...well almost 2 months ago now. i was or am still hungup on him..and i was moving on...until i realized he was still with the girl he started dating right after we broke up. he had some girl on the back burner i later learned that he only started daiting after we broke up. hes been sleeping over at her house and everything so i dont know if hes realyl commited.but hes STILL around her and that stings. anyways when i heard this info i kinda went crazy, after not hearing or trying to contact him for a month. i sent him a heartfelt email telling him how much he hurt me by what he did...and that ive never loved someone the way i loved him and that id never be the same after this it was long, but i did say its best were not together and he never answered. 2 days later i snapped and sent him an email saying, thanks for showing me i could like somebody that much. he preceded to text me....."**** off, before i have to change my number and pretend to move psycho". as if i had been stalking him , which i didnt, id had no contact for a month. i said that thing about pretending to move and changing my number with my ex. why the hellw ould he say something that mean? do u think this girls a rebound and should i be ashamed now that i made myself look so bad???? i wanted him to remember me in a good way , like i didnt need him! god i feel bad! help!?!?! I still live in the same town as him and I'm so scared to see him! i know this guy is a bad guy...but i mean i just dont know if he realy likes her or if shes a rebound..he did say to me at the end of our relationship he thought it would be easier if he found someone else...and stuff like that. and my friend overheard him sayin shes a nice person and they like doing stuff, but ive also been hearing his lifes been falling apart since i havent been around him and not concentrating at work. do u think he just knows theres no way he can fix things with me after what he did? or do u think hes really wild about this new girl...i mean do u really say someones a "nice person" if u really liked them?