Medications Recommended by the Veterinarian for My Vomiting Bird

I’ve posted about this before. My bird has been vomiting for a month—he vomits so much that it piles up inside his cage. He’s constantly eating and then throwing up. His behavior has changed, too; he used to be hesitant to try new things, but now he tries to eat everything he sees. He drinks a lot of water, eats, and then immediately vomits—only to try eating again right away. I took him to a vet, but the vet just picked him up, felt his chest, and prescribed some medication; it didn’t really inspire much confidence. I even brought the cage with the vomit still in it so they could examine it, but no actual testing or analysis was done—the vet just looked at it and remarked that there was a lot of vomit. I offered to show a video of him vomiting so they could see how he does it, but the vet said it wasn't necessary, noting that the amount of vomit in the cage made it obvious. The only question they asked was whether his droppings were black. Honestly, I’m not very confident in this assessment, so I wanted to get your opinions. I’ve heard that one of the prescribed medications, Mycostatin, isn’t highly recommended—I’m not sure about the others—what do you think? Also, I was told to administer all three medications on the same day; wouldn’t that be too hard on the bird? Please help—I really don’t know what to do.