New to Orchids Mold and Yellowing Leaves

[lieuz]

Hello!

I am new to orchids and new to this forum. My fiancee and I just moved to a new house and was given an orchid from my mom! It was such a nice gesture, she is an avid grower of orchids and this orchid is actually from her own collection. It sprouted two spikes and from them beautiful white flowers bloomed and has been blooming for about 2 months. My mom told me the name of the orchid is a phalaenopsis that has white flowers. It was such an amazing 2 months being able to see such beautiful blooms. Being my mom, she came to our house and looked at the location of the home because as a family of avid gardeners she knows that a good facing home has the greatest of advantages. I myself grow bonsai and I grow all sorts. I'm just new to orchids. Anyway, recently I noticed that the flowers from where the first blooms started to wilt and being 2 months into the house I figured it's time for them to wilt. My mom said that they can wilt by the end of 2 to 4 months. So no harm no foul, until I started to notice the newer blooms start to wilt and I know for a fact they have been there for only 2 weeks or so. So I go in to inspect and I noticed that the leaves are starting to turn yellow. The top leaves not the bottom (just yet i'm afraid). The orchid leaf crown have fallen out because it just became super decayed so I took it out. Just a few days ago the leave yellowing is now REALLY pronounced and I simply just touched it and IT FELL RIGHT OFF! I am so worried! Upon closer inspection I notice there is a furry mass by the roots! I believe it's mold and when I inspect the medium it's slightly damp.

With that said here are my specs:

Our house is a southern facing home we get sun ALL day in the front and being winter the sun is most direct into our front bay window where most of our vegetation is at. The orchid is about 9 feet away from that window and we have a white curtain that diffuses light when we are away at work while the window is kept wide open (blinds that is).

I water about once a week when I feel the top inch of the medium is dry.

When I water, I take the ENTIRE plant and submerge it in the sink.

The house is kept at a constant 70 since it's started to get cold we have had the house around that temp.

I do not fertilize and have no attempted to use any fungicide. What are my options here?! I'm really worried about this plant!

---------- Post added at 10:08 PM ---------- Previous post was at 10:04 PM ----------

I also forgot to add that I did do mistings on the leaves and now that I think about it, I'm so dumb because I just realized the crown probably decayed due to me constantly misting the leaves and it pooling right in the crown. Sigh...fail...