8wk old w/ colic & reflux

Hello. We had a natural home birth, which went off without a hitch. Our daughter was born happy and healthy at 7.4 lbs. and 19.5 in. However, at around 2 weeks she started with colicky behavior (screaming for prolonged periods, gassy, etc.). We read a lot about it and realized it was definitely colic. Around the third/fourth week, she also started spitting up more frequently and in larger amounts. We were worried that it could be reflux, so we took her in to our pediatrician. During the visit, the baby spit up and the pediatrician said it was definitely acid reflux as opposed to physiological reflux. He wanted to prescribe Zantac. However, after leaving the office, we decided that was not the way we wanted to go. We did not want our baby on Zantac.

We then took her to a naturopathic doctor and were given probiotic powder and two different homeopathic pellets (Nux Vomica and Cholocynthis). We've been giving these to her for about three weeks (although the pellets much less frequently). We have also been using Colic Calm and Hyland's Colic Tablets since week 3, for temporary relief.

We recently read 'The Happiest Baby on the Block' and Dr. Karp's advice for calming colicky babies has been helping. However, in the past few days, the reflux seems to be getting a lot worse. She spits up during and after almost every feeding. I used to burp her a lot during feedings, but now I am afraid to because I feel it is certain to bring up almost everything she nursed. I should mention here that I have been breastfeeding exclusively. Last Friday we took her to the pediatrician's office again. She was exactly 8 weeks and weighed 9.1 lbs. The pediatrician seemed concerned about this and suggested that we supplement the breast milk with formula. Specifically, our baby had gone from the 25% to the 10% line on his weight chart. He also prescribed Levsin to calm her down. We have not filled the prescription because we read that this can cause constipation, and we believe she is already constipated frequently.

HELP! We do not want to put our baby on Zantac or switch her to formula. But, we don't want her to be in pain, develop an ulcer, or have poor weight gain. We think the colic will work itself out, but we are really worried about the reflux. She is hungry all the time, and we believe that it is because she may be spitting up most of what she takes in.

Any advice would be greatly appreciated. If I left out facts that would be helpful, please just ask.

Is Zantac really that bad? When she is spitting up and crying, I am so tempted to fill the prescription. But then I get my head together and also get worried about what I might be doing to her long term by giving her an antacid this early.

Thank you!