I have this plant that is growing all over. Is it a parasite that I need to remove? This plant is creeping up trees and it is growing through and over all my other plants.
I am pretty sure this is Chalice vine(Solandra species). It is not a parasite, but it does grow fast and can shade out other plants. Prune it back as much as you wish - it can tolerate heavy pruning.
https://www.gardeningknowhow.com/ornamental/vines/chalice-vine/chalice-vine-information.htm
My plant is flowering, but its leaves are yellowing and dropping off. I have tried regular watering and feeding without success. I have it growing in a deep pot which I was assured was large enough for about 5 years. Could too much water be the problem?
Yes, too much water could be the problem. Larger pots hold water for longer, so the plant's roots may be staying wet too long. If the plant's current size is out of proportion to the size of the pot, it's best to repot in a smaller container for now. Also make sure the container has enough drainage holes in the bottom and the soil mix is well-drained.