Paying someone money to cut the grass for you is exactly what you should do. Also find out what the rules are in your community, how long can you let the grass grow until the ticket you, or whatever, and don't worry about getting the grass cut until it starts getting close to that height. Chances are, you'll always get the grass cut before it reaches critical height.

Cut the grass early morning or late evening so you don't have to deal with the heat. If neighbors complain let them know you have a health condition and that you are now on your own and doing the best you can. If they don't like it, maybe they'll come over and cut the grass for you.