Well, you are British, and you know what they say about Brits and their teeth ;)

Seriously, you need to switch dentists. Most likely a problem with your jaw alignment.

This is making my cheek hurt just thinking about it. I understand your pain OP

shit happens to me ALL THE ******* TIME

That sucks! Have done that!

I hate that shit, it happens to me all the time! My Dentist said it'd cause I have a yuckmouth! Get your teeth fixed, you'll be ok?

That normally happens when your jaw isn't aligned right. My aunt and grandmother had some sort of realignment surgery and they both haven't had problems since. Hope it gets better :)

Have you tried maybe just chewing a bit slower?

Mine do this too. I was told it's because I have a small mouth and has nothing to do with chewing fast or slow.

Try having them check out your jaw. I always bite my cheek and I think, rather than my teeth, it is the way I move my jaw.