10 mgs or even 25 mgs of Elavil is a low dose and not likely to cause serotonin syndrome.

When you were feeling normal, it did not mean you were ready to stop the Elavil. A long slow tapering off would have been better. Your normal feeling was with drug support. Removing the drugs removes the support.

Did you also return to a full level of activity?

Again, normal is not a sign to return to normal activity quickly. The return to normal activity should be slow and in stages.

What did you do on holiday?