The first thing you should consider is that orchids (phalenopsis blooms many months, but not indefinitely. all the flowers die off and the spike is left as a bare branch. Once you are ready cut that off near its base.
You could have over watered. The bast thing is to remove it from the catch pot and dump the old water and see how it goes. You could check the roots, but just letting it dry out on its own might be proper here. The stuff it is in needs to remain somewhat damp though. Do not let it dry out until it is papery dry.
See how that goes.
