ruptured anal gland dog

guys im at my wits end here... our beagle mix had a ruptured anal gland last night and it was honestly the worst thing ive ever dealt with (and i have 3 kids so thats saying something). were in pennsylvania and of course this happens on a sunday when all the regular vets are closed. yesterday afternoon i noticed him scooting on the carpet more than usual and then boom... there was blood and this awful smell that i cant even describe. looked it up and yeah pretty sure its a ruptured anal gland. the area looks swollen and angry and hes clearly in pain. took him to the emergency vet (goodbye $400 just to walk in the door) and they cleaned it out gave us antibiotics and pain meds but said it might happen again?? like what?? they mentioned something about expressing glands regularly but nobody told me this was a thing when we got a dog. now hes wearing the cone of shame and keeps trying to lick the area... barely slept last night because he was whimpering and i felt so bad for him. gave him the pain meds but it doesnt seem to help much. also trying to keep the area clean but he freaks out when i go near it. the vet said something about changing his diet and adding fiber but didnt really explain what that means... just handed us a $600 bill and sent us home. now im googling "ruptured anal gland dog" at 3am like an idiot

has anyone dealt with this before? how long until it heals? and how do i stop this from happening again because i seriously cannot handle another night like this... between the smell and the vet bills im about ready to lose it