Plz help identify my house plant..it's dying! Needs urgent TLC!

I have had this house plant for a while, and it has been doing great. Recently it has started going downhill fast, and I need some help identifying it so I can get information on how to bring it back to health. Please help me solve this dilemma, as I have a huge emotional attachment to this plant. I appreciate any help..thank you!

 

Schefflera.

 

Looks like Schefflera arboricola, Umbrella Tree.

 

Assume that this is either a photo of another specimen, or of your plant in happier times.
If you could give us one of your plant in its currently sad state, we could help to diagnose its problem(s).

 

Here is a picture of my plant. I have recently re potted it due to it's sad state. I think the problem began when I noticed I over watered it a little bit. I've made sure not to do it again since that happened about 10 days ago, and it still looks like it's declining when looking at the top 2/3 of the plant. The bottom 1/3 seems to be doing great once again, but not sure if the upper half will hang on. I think maybe I've been under watering it now since leaves are starting to curl up, and a few turned black. Some are also dropping pretty bad. I just now added about 2 cups of water, and I keep it in the window which gets sunlight for about half of the day. I sincerely appreciate everyone's help. It means a lot!

 

Looks pretty dry to me.
When you water, put your plant in the shower or take it outside and give it a gentle, thorough soaking, till the water runs out the bottom of the pot and the soil is good and moist all the way through. This is especially important with new soil---like a sponge, it absorbs best when evenly moist. The roots have to have abundant water to get the moisture to the rest of the plant.

 

Schefflera likes dry and warm, not dry dry but not over watering.
Any plants won't live in the pot/planter forever, sometimes, a plant just dies because it has been too long in the pot/planter. Some plants live for 8 years in the pot, others may live shorter.
Since you changed the pot to a larger one and changed the soil, cut off the dying top portion, it may branch and turn into a nicer plant in the future.