Hi A.,
I recommend reading Healthy Sleep Habits, Happy Child by Dr. Marc Weissbluth for age appropriate sleep needs and schedules. With this said, I would move his bedtime much earlier to 6:30-7pm and try moving his nap to 12:30-1pm. Dr. Weissbluth, an expert in the field of sleep (check his credentials out), states the most common reason for too early a wake up is too late a bedtime. By going to bed too late and attending to him at night, it is causing him fragmented sleep which isn't as restorative which causes him to become constantly overtired. I would immediately move his nap and bedtime earlier by an hour then if he wakes in the early morning hours, wait 5-15 mins before responding to see if he puts himself back to sleep. When you do respond, try to soothe him without picking him up or talking. Remember, it can take 1-2 weeks of consistency to change a habit and this is just a habit he has developed. By responding with rocking and/or breastfeeding you are inadvertently reinforcing this habit. I have found that one of the hardest things to do as a mother is to distinguish between needs and wants. Your son NEEDS to learn to go back to sleep on his own but WANTS attention from you. The extreme action would be to let him cry it out. It does work faster but is harder on the parents! As to the teething, the discomfort is really not as bad as many believe. (check out my profile for my experience in the dental field) Try giving him some Tylenol or Motrin before bed. If you want more info on Dr. Weissbluth's methods, email me. I firmly believe that alot of problems can be corrected with healthy sleep.
Sincerely,
L.