Orchid with mildew smell on moss

[BrklynOrchid]

I recently got an orchid as a gift. It is large with two stems, thick fat flat meaty leaves, and white flowers with light pink in the center. We were getting along great until I went away for the 4th of July. I gave it some extra water because I was afraid it would get to dry and hot in my apartment but it still hasn't dried back out and there is a little bit of mildew smell to the moss. The flowers aren't wilted at all but they are looking a little vainy and more wrinkly then usual and I don't know what to do to help it get back on track