I would work with what you have. I do not think you are in a total disaster area. To me at least I would not feel that it was at this point. It could have been much worse.

You have to find out from a shop just how much material they would have to remove to flatten the head. That 2mm thicker gasket may get you by. Remember it is for situations like yours and you are not the first.

Picking a good automotive machine shop is always the path to satisfaction usually.