"How Can I win him back and prove that we deserve each other "

Before you do anything , make sure you're really really ready to make this commitment again. If he has been talking to you all day chances are he still cares a lot about you too.

The best way to prove to someone you've changed and are willing to give it your all is to tell them, and make sure they understand that you mean it. Tell him how happy you are to be talking to him and how stupid you were to make the mistake of letting him go. It's not going to go completely back to normal like it was 7 months ago right away. It's going to take some time to build back your relationship and you might struggle with some stuff but if you both truly want it then it will work out.

So just keep an open mind, and make sure he realizes how sorry you are about what happened and how badly you want thinks to work out. The only way he's going to believe it is if he feels like he can fully trust you. So for now, just work on getting his trust back.

Good luck and I'm glad things are working out!