How do you know if someone has moved on or is still holding on to you?

Its been about 10 days i broke up with my ex, he meant the world to me, and still do. We dated for a while, he was the first to tell me he loved me, he askd my parents to marry me and even proposed to me. Which i said no, because i wasnt ready for such a big step. I had known him for 2 years, and dated him for 3 monhts. When i broke up withhim, he begged me to get back with him which i tried too do and then he didnt want too. He then kicked me out of his place and compleltely been ignorning my phonecalls, texts and even emails. HE has blocked me from IMs and all. Can someone please tell me, what to think? Is he upset as much as i am and this is his way of dealing with it? he was awfully nasty to me the night and the next day after the break up. A totally different person. I hope someone can shed some light on this for me.