Big hugs honey... I too would steer clear of Phenergan - it is not to be used for kids under 2. It can depress their respiratory system - & has been linked to not very nice outcomes. As someone else said it can also have the opposite affect and wind them up like tops!
Sedation of kids isn't something that I would suggest.

Trillian has given some good suggestions their re the bottom rash. Darling I hope this all settles down soon - you must be so doggone tired. I am telling ya I wish you were still close and I could help you practically. (not right now as I am as sick as a dog myself! ).

Big cuddles...