Uhm 4 responses in a row said, and I'm paraphrasing, "lose the belt". LOSE THE DAMN BELT. Wear it for bicep curls to get it worked in or something but lose it for squats and deads. Assuming no structural abnormalities a belt won't help you GET stronger as a belt holds your core in for you. WORK your core, lower your weight and work on perfect form. Make sure you have good ankle flexibility and work on it if you don't. Work on HIP flexibility; mine sucks but I work on it still. DO GOODMORNINGS!! I noticed no one said this. Goodmornings are the shit; start with the bar so you get the form PERFECT, then some 25's, and SLOWLY add weight, 5% eo workout or so. If you want to use a towel for comfort go ahead; DON'T let that bar roll up on your neck either, that's bad form. Hyper extensions WITH a serious dumbell for high reps; not 100 but 25-50. I'm nearly 50 and every 3 weeks I'll do hypers with 100 for sets of 50 (cause that's as high as I can count in one set)
