It depends on why you had to stop flying and how old you are.
If you had to stop because of age rules, then you can hop over to another company that doesn't have such a low limit on age. If the age limit is a state one, you can sometimes fly for a company that doesn't fly over that airspace.
If it was a medical reason then you have a couple of options depending on the severity. Some go on to instruct if they can get their medical back (albeit with restrictions). If it's a total no go with the medical then ground work is the only thing left. There's many areas available, you can teach ATPL subjects, type rating ground schools, sim instructing. The choice is limited by your ability and the market.