If you work loading boxes in a warehouse, then you can no longer perform that job. If you sit at a computer all day (or most of it) then you should be able to work. You may have to retrain to a new field if you want to continue to be productive. Only you can decide how your illness has affected your ability to complete your work successfully. Going on disability is a long, tedious process, and it can take years before you see money or get approved, if you get approved at all. Plus, you have to have a good doctor to back up your claim, because they are the ones that fill out a huge amount of the paper work.