what are my chances

I am a 51 year old male with spinal stenosis, ruputered disc L 3,4,5 and S2, I am in severe pain if I walk more than 15-20 minutes at a time , try to bend and pick up items,0r sit for more than 45 min-1 hour. I do not sleep I am up and down constantly even at night. I have diabetes, hypertension 3 bp meds, chf take 120 mg lasix daily, depression, morbid obesity to name a few. I have continued to work and have been on extended leave twice this year and my time runs out 12-6=11 so I will be leaving my job. Would I be a candidate for disability and when should I apply