You aren't tone deaf. Especially if you can tune a drum set. Whether you really can tune a drum set well might still be in question, since I think a lot of people deceive themselves about how well they tune drums!
I suggest you get Dan Huckabee's DVD The Formula of Music. It's not cheap, but it will help you a lot. If you have a guitar or other stringed instrument around, learn to tune that. Tuning a tympani will be more like tuning a guitar than like tuning a drum set. You need to hear a pitch and match it.
I do like Anthony's suggestion to learn to sing scales, but the problem there is you won't know if you are on pitch without a tuner. You could get a voice tuner app, but I think tuning a guitar would a better place to start if you have one around.
Statistically, I've read that 97% of American Males own a guitar even though 99% of them can't play guitar (joke). So I figure it isn't unlikely you have access to one.