Hi M.,
I'm unclear what you mean about waking your son to breastfeed. Do you mean at night or from the frequent naps? Also, if you focus on keeping your diet full of nutritious foods, so that your milk supply is also, you shouldn't have to worry about supplementing with formula.
I have to also mention that the first four months are the hardest on you, until he starts eating solid foods. For me, it was on average every three hours. (Solids were a joyous time in regard to breastfeeding.) You might try contacting http://www.lalecheleague.org/ La Leche International is an international organization for breastfeeding mothers. They have free meetings, consultation resources, etc. They could probably refer you to a lactation specialist.
I encourage you to keep trying. Maybe a lactation consultant will get you past the difficulty. (I had one while I was still in the hospital and don't believe I would've gotten the latching on part down if it had not been for that.) I know it's a major challenge (I breastfed my daughter until she was 2), but try to hang in there. I want to also say though that if it seems impractical for you, don't beat yourself up for it, if you wind up only doing formula.
If you have any questions, feel free to email me at ____@____.com luck,
L.