You would never think it, but the food you eat can wreck your sleeping ability and quality. You are nursing. Try eliminating gluten and dairy from your diet, and his if he is on solid foods, and see what happens.
I am on a gluten and dairy free diet. My breastfeeding 6 month old sleeps pretty well. I had a dinner than had dairy at a restaurant one night, and he didn't sleep well for several days after, until we both cleared it out of our systems. It also gave him gas.
You can even have babies tested for food intolerances through www. enterolab.com. It's a stool test, so easy for babies. Just send in his stool (1/2 cup needed for testing). Order test kit online. No doctor referral needed. They email you the results.