Hi--are you available to chat? I can't examine or treat but I might be able to give excellent advice. The first issue I'd address is easy--the bad breath.
This is most likely from not completely closing your mouth at night BECAUSE of the mouth guard and/or the adjustments--dry mouth/mouth breathing causes halitosis and using Biotene might help, as well as brushing your tongue.
On the other hand, I would make sure you take sinus hygiene measures to make sure none of the halitosis is due to post-nasal drip you might not even perceive. (At worse, it will help ward off future sinusitis)
So when you can chat I'd like to try and address the temple pain.
Hello Doctor, are you Free today at all ? regards Mark
Hello Mark--yes--will be back in about or less than an hour and post then. Did you try what I suggested above?
Will await your answer, Mark. I hope the above helped previously. I have some suggestions for the jaw ache. I am on the West Coast of the US so our time difference might interfere. Will be in and out as today is a holiday here.
By sinus hygiene measure, I meant washing your nose 2-3 times/day with warm salt water with a neti pot or NeilMed bottle (available in UK) to decrease pollutants and mucus in sinuses. Perhaps trying loratidine or fexofenadine and a steroid nose spray but the washing is bottom line.