Depending on what meds you were on, some of them seem to "poop out" after a while, so your symptoms may come back. Changing meds will usually be effective to get your response back, and after a while, if that new med poops out, the first one will usually be effective again.

In the meantime, the more you worry that this set back is going to create problems for you, the more likely that is. I know that it's damn near impossible to get your mind onto something else, but if you can, that's the best way to stop the worry from becoming a full blown obsession. But I"m guessing you already know that, right?

I wish you good luck, and hope that this set back passes quickly for you.