Did you add fish food or some sort of ammonia source to the bucket for the filter to process? If you didn’t then your filter is most likely not seeded any longer.
As for what I would do, you don’t really have that much time to do all the necessary steps. A more experienced keeper may get by, but this isn’t your scenario. I would see if my LFS can watch the little guy while you’re gone, possibly have them medicate it as well. I’d ask and bring the meds you want dosed. Or you can purchase seeded sponges from the LFS or a hobbyist and then you will have a cycled tank. I’d go for option 2, but that’s up to you.