how often for gripe water???

So something in my diet is upsetting my sons belly BAD. I think its dairy bc ive always had issues with it, so im cutting it out. Its only been like a day since i stopped though so his cramps are horrible.. I feel terrible.. Anyways, we give him gripe water at night and he goes to sleep. If not, hes up til like 5am screaming. So my question is, is it harmful to give him it every night?? If so, how many days should we wait before giving him another dose?? Hes 3 weeks old. The box says 1/2 tsp, four times a day. We do one time a day (before bed, like i mentioned) TIA :)