What's the best way to get over being dumped?

I was with my girlfriend for 3 years, and we lived together whilst we were at college, and then for a few months afterwards.
Then completely out of the blue she dumped me.
The thing is, she would do anything for me and I always thought if the relationship was ever going to end it would be on my terms.

So I Have gone from being in a great loving relationship, to being made to pack my stuff and leave, she has not spoke to me since, and won’t answer if I message her on Facebook.

But the thing is, I just can’t get over her, and every day I see things what remind me of her.

I know I need to just toughen up and sort my life out, but I’m finding it quite hard to do, it all came as a shock.

Anyone been through similar experiences? And can offer me some advice.