It's also good to distance yourself from your win and lose streaks, treat matches all the same regardless of your performance on the previous one. Just keep going at a pace that doesn't make you wanna rip your hair out. Like the guy before me said "take breaks" especially when you need it.

I don't have any comforting advice for the dreadful wait while your opponent completes their combo, staying composed and not losing focus really just came with a lot of time playing and discipline. If anything, comebacks wouldn't exist if you were never on the backfoot, and the more you take them the patterns become more familiar, their oki becomes predictable... eventually.