Doc, don't give up!Singing on pitch is a bit like shooting from the hip. When you first try it, you miss a lot. The more you do it, the more accurate you get.
Don't be afraid of voice teachers. There seems to be a misconception, particularly among folksingers, that if you take voice lessons, you'll suddenly start sounding like Luciano Pavarotti or Bryn Terfel or Cecilia Bartolli or Anna Moffo. Not so! Many an aspiring opera singer wishes it was that easy!!
A good voice teacher can help you with pitch accuracy. And a good voice teacher can teach you correct vocal technique -- which is to say, how to sing naturally. This includes such things as breath control and relaxing your vocal apparatus so you can sing without strain. Strain can lead to such things as hoarseness and laryngitis and eventually wreck your voice.
I've had a lot of voice lessons, and if the misconception were true, I should sound like Ezio Pinza. My voice is classed as "bass-baritone," as his is. My voice is strong and resonant, and still in good shape for my age, thank heavens -- but since I don't try to sound operatic, I don't.
Think about taking some voice lessons or getting some vocal coaching. Believe me, it can't hurt.
Don Firth