How can i recover from severe deconditioning due to months of being couch bound because of covid and the pandemic? wide spread pain in my body especially my lower back and lower abdominal?

Start exercising. Any exercise, like walking, treadmill, cycling, elliptical, jogging etc. will do. Start with the intensity and duration that is tolerable. Gradually increase the intensity and duration of your exercise so that after 30 minutes of exercise you are sweating. Drink enough water so your urine is mostly colorless. For diet: http://www.choosemyplate.gov/