your usually always better off working till you cant, cause the longer you pay into the system and the more money you make , the more you get back when disabled. so if young your better off getting retrained or schooling for into something you can do for 20 plus years,
your also better off working for someone as opposed to being self employed, your benefits are the same , but when self employed you pay twice as much , when an employee you employer contributes too.
you also need medical documentation as to why you stopped working. i believe stopped due to sci complications and injurie is enough if your injury is thoroughly documented.