for as long as I can remember I've always slept on my right, but I don't know what is best for sleep.
Henry, you're over-thinking this just a tiny bit!
It doesn't matter at all what position you sleep in. And in any case, it's guaranteed that you don't always sleep on your right side. What you mean is that you always fall asleep on your right side, and usually wake up on that side. We all change positions regularly throughout the night, at least during the non-dreaming phases of our sleep. If you'd really stayed on one side without moving all night you'd develop pressure sores, even at your age!
Left
I personally sleep on my left with plenty of pillows for comfort. You can a read a book or magazine before settling down. I do this regularly it relaxes me.