Hey yo whats up guys,

Ive been working out on a strict routine for a while, but life got in the way and i had to stop for a couple months. The other day i tried to do one of my normal routines and WoW- i could not get close to even finishing it- i was sooo tired after a few reps.... do i need to start low again? and mabye itll get back to normal? did i lose all my strength!?
IVe also heard it was good to take a break to break the plateau...i do know i was at a plateau too when I stopped lifting