I think I have bruxism + insomnia + sleep apnea. Help?

Seek dental help. See a dentist trained in dental sleep medicine. Bruxism (tooth grinding) & insomnia are signs of sleep apnea. A trained dentist can see that you have the correct diagnosis by a sleep specialist and if appropriate can make an oral appliance. In 2006, the american academy of sleep medicine published treatment parameters for mild-moderate sleep apnea & if CPAP not used, an oral appliance can be used.
Diet. As I have answered many times, high calorie malnutrition is the major clue. All these symptoms are due to compromised biochemistrfy in brainstem and limbic system. I would bewilling to bet that you have a severe degree of vitamin b1 deficiency induced through a "junky" diet. Get rid of sugar in all its forms and read my blog "oxygen, the spark of life" that you can google. See a nutritionist.