I don't think 22 is too old. The guy I train with started a couple years ago and he's 27...and he's really good. Seriously man as long as you dedicate yourself to it and train harder than the guy across the cage/ ring from you, I definitely think you would have a chance.
Oh yeah...also don't forget to choose the right weight class for you to fight in. You really need to find the division you excel in. i.e. Franklin moving from LHW to MW, or Diego moving from MW to WW.