Nah, haven't went to any surgeons or anything like that. And I live in the UK. Not really sure where to go about it.
Do you think jaw surgery would sort out the problems I've mentioned above? I'm also starting to wonder if I have some form of sleep apnoea after reading some of the symptoms
1. If you are breathing through your mouth mostly, it could be that you have a small airway. It is possible that jaw surgery could give you a bigger airway and enable you to breathe more naturally through your nose. Also, you might want to have an ENT check to see if you have a deviated septum. That could also effect your breathing in a drastic way.
2. Your bite is probably off. Even if it "seems ok" to you, if closing your mouth feels akward, there is probably something going on with your bite. As one of the above posters mentioned, based on your profile I would guess you have a Class II bite, but of course I would need to see a photo to know for sure. Do you have a gummy smile? Do you have an openbite? A surgeon should be able to tell you all this info
3. If you have a skeletal issue, i.e. your mandible failed to grow to it's normal size, then muscle exercises alone probably won't help you. Just my opinion, but if you fix the underlying cause of your muscle strain, then your muscles should be able to function the way they were intended to and they should get stronger
4. If you live in England, you probably have the NHS in which case jaw surgery might not cost you anything. If your bite is off, it seems like many posters in England have gotten their surgery paid for.
I think overall it is definitely worth going to a surgeon for a consult and go from there.