1. You have to earn his trust back. Trust can be hard to earn once you’ve lost it, and it can take a while, but if it’s really worth it, you’ll put in the effort.
2. Love is indescribable. It’s what pulls you out of bed in the morning and puts you to sleep at night. There’s no way to fully understand it unless you’ve felt it. As for your second question, you just know. Fully. Entirely. 100%. You don’t have doubts, no maybes, no “well I think I’m in love”s…you know when you are in love.
3. You should probably cut off contact to move on from him. A bad breakup is hard to get past, but it’s easier if you aren’t faced with a constant reminder of it. Take some time for yourself and do things that make you happy. The only thing that can fully heal you is time.