You have posted this in the LPS forum and a Toadstool is not an LPS, it belongs in the Soft Coral forum.
I'll answer your question anyway as I've got a few of them. They prefer High light and good med to fairly heavy flow. From the looks of where you have it placed it has neither.
If you take a little time to search anything you buy for your tank fish, LPS, SPS or leathers and soft corals you can go to the Live Aquaria website and find each thing there is a complete explanation of each and it gives location preference on each in the description.
So find it a place with med/high light and med to high flow and it will become happy again.