I had to take a year off, starting back was tough, I altered my routine to be higher reps for the first six weeks, and then lowered back into my preferred rep range in order to build my strength back up a bit. One thing I did differently than "normal" is after the first six weeks, when I was trying to build up some strength, I did more "negatives" and focused on the eccentric motion. For some reason I have this stuck in my mind that it helps me get stronger faster. I taper this off almost completely in my "normal" routines, but I am no longer looking to lift increasingly heavier weights due to some health issues.
Don't get discouraged, I've been where you are a couple of times, and at first it seems like you will never get it back, but you will.