Phalaenopsis Orchid with yellow/brown leaves

[Arose66]

Hello everyone! This is my first ever post on any orchid discussion board, as I have been unable to find answers online as to what is wrong with my orchid! I am new to the world of orchids (I received my phalaenopsis orchid as a gift in April for my birthday) and I want to do everything I can to to keep it alive and blooming.

I live in an apartment without any sort of backyard area so my orchid is an indoor plant. I have a few windows however my apartment is pretty small and I know my orchid doesn't get as much light as it probably should.

The first time I watered my orchid I had no idea what I was doing and I accidentally let it sit in water for 3 or 4 days. I realized my mistake and drained the excess water from my pot, and have only re-watered it (properly this time) one time since. I recently purchased "miracle grow orchid food" which I plan on using the next time I water.

My orchid began losing its flowers about one month after I received it, with all of them falling off about 2-3 weeks ago. Since then my orchid leaves have turned yellow and brown on the tips, and have started wilting as well. The newer leaves at the base of the plant are completely yellow and very moist feeling when compared to the more established green leaves on the rest of the plant. The stem of my orchid has very recently dried and curled up at the end. When I take it out of the pot to look at the roots, although many of them are green some do have a brownish appearance indicating root rot.

My orchid is definitely dehydrated, but I'm having trouble figuring out if it's because of under or over-watering. As far as the existing damage goes, should I cut off the seemingly dying leaves? What about the roots, is it possible it needs to be re-potted? Maybe my apartment just isn't suitable to have an orchid? Any suggestions would be greatly appreciated. I will attach pictures below!