Weight Loss Plateau - Help Needed

I have been on Weight Watchers for a couple of years now. My wife and I religiously attend our weekly meetings and read nutrition labels like pros. I initially lost 90 pounds, but over the last six months I have gained back about 20. Part of the problem is that I injured my shoulder and my back (rotator cuff tear and chronic compression fracture). But the real problem is lack of following the solid weight watchers principles that got me here. I need motivation to begin tracking my points again and getting the daily exercise (even when it hurts the injuries).

My eating habits are definitely better than they ever have been. I need to get going again on the weight loss track. Can somebody out there in blog land tell me the secret to staying on track long term?