I used Target brand gas drops. My son had really bad gas. The things that helped most were:
Me eating less gas causing foods, onions, beans, dairy.
I drank large amounts of fennel tea (I hated the taste but it helped and now I kinda like that anise flavor)
Baby aerobics (I would sing row your boat and press my sons legs to his tummy, I can't believe how much gas this would expel!
Warm lavender baths before bed.
I know how hard it can be to have a gassy baby, hang in there it will get better! It takes time for babies to learn how to use their bodies. Hopefully it won't take too long, it took my son six months, but I got really good at helping him thru it. Best of luck!