My 3month old cries uncontrollably

Need help idk what to do, my baby is inconsolable when she cries, it's all the time for hours, I mean hours. She'll sleep for shot periods then cry none stop, she refuses to breastfeed out of nowhere it's a fight to feed her the same with the bottle. She has gone a week without pooping, she has gas all the time. I burp her after every feed when she does feed. I need help idk what to do anymore I've tried different nipples, different colic meds, I've taken her to the Dr 2 times each time they say she's healthy I know that. She has an appt with a different dr. She is my 4th baby, if you are going through this please give me advice or has gone through this please give me advice.