Why is my phone running so slow?

Over the past two days, my phone has taken up to five minutes to load one app, and I keep getting a message box that pops up saying "______ app is not responding. Would you like to close it?" I went through and deleted a bunch of pictures, apps, games, videos, etc. and nothing has helped. I've taken the battery out and let it sit and cool off, but that hasn't worked either. Whenever I charge it, the phone gets extremely hot and dies very quickly.

I'm afraid my phone is about to kick the bucket.