Actually I went through the same, but I found out that if you gain any exp orbs, Your lvls will automatically fix and be how it was before.
For example:
If you enchant and/or fix on anvil a lvl 10 exp on a pickaxe, If it takes all your exp away but doesnt combine the enchant, and you would be at lvl 0 exp. Just go grab some more exp, and it will fix it, and go back to lvl 10 exp.
At least that is what I found out how to solve it so far, I hope yall can work this out as well until Micah or bk can find a solution c: