Don't replace all the filter media at once, or you will be throwing away the beneficial bacteria and your tank will have to cycle all over again. If the media is filthy, rinse it in a bucket in some of the water you remove from your tank. That way the bacteria will stay.
Partial water changes sound good.
Helpful fish feeders during vacation often get enthusiastic and give too much. Sounds like your fish pigged out while you were away.
joy to the fishes in the deep blue sea
55, 30, 30, 20, 10, and 10-gal. freshwater tropical tanks