This sounds like a minor setback. Setbacks are setbacks. They are not the worst that can befall you by any measure. Having been there many times, I know the despair they can bring, but we both know that in two weeks tops you'll be back to baseline. Setbacks happen. They pass.

When they happen I find it helpful to go about my daily routine and not start acting as though I were sick. They includes eating normally. Acting as though you feel bad will make you feel worse.

I think the best response after a setback is to accept that you will probably feel a bit worse for a little while, remember that it will pass, and go about your business.