If it's not wisdom teeth, then you're likely suffering from an acute flare up of your right TMJ. (Where your lower jaw attaches to your skull.)
It would appear that you grind your teeth habitually, whether consciously or subconsciously at night. That's probably why you've tried wearing a mouthguard at night. And in recent weeks, whether it's because you're under elevated stress, you're grinding your teeth more aggressively than before. This would explain the back molars
The clicking sound that occurs when you open and close suggests that the meniscus at your TMJ is not allowing smooth movement of your right condyle (of your lower jaw). So the joint is irritated and swollen, which is why when you press on it, the pain radiates upward toward the temple.
I'm also wondering if whether your store-bought nightguard is contributing to the problem. Nightguards can be very helpful for patients who grind their teeth. However, a poor-fitting nightguard (usually the case with store-bought guards) can actually cause you to clench and grind your teeth more.
At this time, I would recommend that you stop using that current nightguard altogether. Continue to take an anti-inflammatory (Advil/Tylenol is fine) to try and reduce the inflammation of your TMJ. You'll also want to get some ice and put it in a Ziploc bag, wrap it up with a thin hand towel and apply the ice pack to the right side of the face, just in front
of your right year. Hopefully this will help reduce the swelling in the joint. Apply the ice for 10-min on, and 10-min off for about 30min-1hr as needed. Also, if possible, attempt to reduce your stress level.
Assuming that it was the poor-fitting nightguard causing your bite to be off, resulting in additional clenching and grinding, your joint and right side of the face should start to feel better in about 3-5 days. So if in 3-5 days, you're feeling better, then DO NOT ever wear that nightguard again. If you still need to wear a nightguard because you do grind your teeth habitually, then you'll want to see your dentist
and get a custom nightguard made. Custom nightguards will fit properly and be balanced so that your bite won't be off.
If possible, you should also make an appointment with your dentist to evaluate your TMJ. At 22, it is unlikely that any permament damage has occurred to your joint, but we want to do everything that we can to prevent the problem from getting worse.
Jul***** *****, DDS