Please Help, Relux??

I have a 7 week old that was just switched from zantac to prevacid. She cries after eating, bobs her head left and right and can’t finish her normal breastfeeding session. She will only eat 3-4 minutes instead of 8-10. We did not overlap zantac and prevacid since we were out of zantac. The doctor said it was okay. We did this switch over 4 days ago. She is spitting up more now and crying and bobbing at meals. Is this reflux? I am at my wits end with trying to figure out what this screaming is. She is screaming bloody murder… I need some insight why she is doing this between reflux meds. I thought it was colic because she cries ALL THE TIME. We can’t even get her to sleep other than in our arms, car seat, or swing… When she falls asleep we put her in the crib and she wakes up 3 minutes later crying. The cry out method doesn’t work… Please help!