I'm here for a hand-hold. I know how it feels OP, and believe me it does get better.
The single best thing I did for myself when my ex walked out on me was hold on to my self respect by not contacting him - same goes for you - he has made it clear. He knows your number, if he wants to talk to you, he will.
By holding on to your self respect, you can hold your head high, know that you've done the right thing and be proud of yourself. This stood me in good stead a few months on from my breakup when my ex behaved like a childish arse by running away and hiding from me when he saw me in the pub. If I had been texting/calling him begging him to come back at the beginning, then his behaviour would have been justified. Since I had not done those things, I knew that he was just being a giant tit.
4 years on, I'm still proud of how I reacted, and I still reap the benefits. Please do the same for yourself - protect your future self by holding on to your self respect, don't text him.
The second best thing I did was to keep myself as busy as possible during those agonizing first few weeks. Do something, anything, every day to keep your mind occupied. It won't make you forget about him, you'll still hurt, but it will help you see that there's a life out there away from him.
You will feel better, it takes time, but it will happen