It is far more common than most realise.
I have a fidget spinner, every time I catch myself starting the behaviour, I pick up the spinner, and spin it once, I then watch and wait for it to stop spinning, before I carry on whatever I was doing before/during the picking/biting.
I used an example to myself, to ferment this practice to myself.
In the game Titanfall 1, you could manipulate your character in a specific jump pattern, called bunny hopping, to make your character move faster than the developers originally intended, this action became second nature to me, after over a thousand hours of playtime.
When they released Titanfall 2 this was no longer possible, so players developed a new way to bunny hop, which was drastically different. the issue was, if you attempted to bunny hop the old way, you ended up actually going slower than just moving normally. 
It took me a long while to break the habit of attempting to bunny hop the old way, but because of this, the game inadvertently introduced a punishment/reward mechanic, where you were punished severely for attempting to bunny hop the old way, and rewarded for doing it the new way.
I found, due to this I was forced into adapting.
The way I correlated this in my mind, is that if I caught myself chewing/picking/clicking joints, I would implement the punishment. which is waiting for the fidget spinner to stop spinning, the real life equivalent of being forced to go slower.
My brain works in funny ways, and this method worked for me. I have no clue if it would work for you.
There is also the added nuance, that this method occurred to me while I was tripping balls on psychedelics, so the associative memory is very powerful.
But, you’ve taken the first and second steps, first being noticing there is an issue, second knowing what the issue is and putting a name to it.
The third step, would be to start taking steps to stopping the negative behaviour.
Edited to add, I also had repressed memories released to me, which highlighted why the behaviour started in the first place, an abusive childhood, this is apart of why the associative memory is so powerful, maybe if you could get to the root of why and when you started having the problem too? (I don’t mean to imply your childhood was abusive, it could be a whole plethora of reasons, or none at all.)