Sick baby... Breastfeeding? Or formula?

Mindy • So excited to have our first. A little boy in February!
I have been fully breastfeeding my two week old since day one: he gets really bad tummy aches at night only and has trouble pooping. I tried changing my diet to eliminate what's causing him to be so sick all the time with gas, spit up and having trouble pooping but nothing has helped. I just started using gripe water to ease his pain and fussiness. It's been late late nights for both of us with this. What would you do in this situation?! I am stuck because I feel so helpless that I can't do anything to help him more. I've almost to the point on stoping breastfeeding and going to formula to see if he would be better, I feel like it's my fault he is sick and has these problems. :(