Hi, I am so sorry you are feeling lost.
Always remember that submission should come from strength and never from weakness.
The first thing I would like you to do is to remove the word "can't" from your vocabulary. You CAN.
Understand and accept that if you can't find him when you need him, he is not the Dom for you.
The Dom for you will always have your best interest at heart and be there to pick up the pieces, especially if he was the one that broke you down for his own use.
Aftercare is more than just a few moments after a "scene"; It is ongoing and nurturing to allow you to grow as a sub (& heal if necessary).
Once you accept that he has failed you, it will be easier to let go and to begin to build a bond with a Dom that will cherish your submission and care for you, because ultimately, that is what enables you to serve his needs.
For a sub... "The best way to get over someone, is to get under someone else" .
But first, do some self worth and validation exercises,.. some word clouds and vision boards about yourself, your submission, what you have to offer, what you desire for yourself, and in a Dom.. and be strong enough to not settle for any Dom that does not align with your vision.
Get up in the mornings and Bow in front of a mirror & remember that when you are not collared, you serve your self first.. Look at yourself , all of you..feel beautiful, intelligent, strong and sexual...Remember who you are as a sub, and once you know that, AND feel good about it, you are ready to make yourself available to new Doms,... and unlike your past Dom, they won be hard to find. Be strong precious. You are a a gift.