If I were you, I would stop the meditation classes for a while. I bet he will stop too. And then you'll be free to attend again.
I would make clear with my actions, as well as with my words, that I do not wish not only to encourage but not even to stand a coward who comes in when you are not there to take his stuff away.

You are so upset because you are suffering from a kind of double shock: the first being the separation and the second the abruptness of it.

I would stay away from him as much as you can, heal your wounds, try to understand that maybe your relationship was not safe before he went away.
You seem to think that working on things will make them ok, in time. Not always, i'm afraid. You must be in the frame of mind of really wanting to change yourself to save the relationship.
Looks like he did not think this way.

And, if I may add, i guess you should rethink your idea that all kind of problems can be solved. Many times it's much better to let go of that partner, because the work involved to keep the relationship going would be too much.

I think he was not the right person for you and once you will recover from the shock of the loss and how you lost your relationship, you will probably thank him.