Hot and sluggish S5?

[SexyJesus]

I got my S5 when they first came out and over the past 5-6 months the phone has been getting more and more buggy.
The past week or so my phone is always hot. Even if i haven't used it in a while.
It has become very slow and sluggish and sometimes the screen turns off by itself. Apps stop working while I'm using them and sometimes it takes my 5 minutes to even unlock my phone bc it keeps glitching. When I'm not using my phone and I get a notification, the screen lights up as normal, but it won't turn back off without me turning it off manually.
I don't know why it's happening or how to fix it. Please help.

 

[AZgl1500]

Every time my phone has slowed down, I take a good hard look at what I did to it recently.

The last time was about a month ago and I had added a baker's dozen of new apps to experiment with.

I then opened up the Apps Drawer and took a good hard look at every app on my phone. IF that app had not been used in the last 3 or 4 weeks, it got deleted.

If an app did not have any redeeming value, it got deleted.

Then I did a restart and wallah, a nice zippy phone again.... I didn't even have to purge the cache partitions. File Explorer would ask me if I wanted to remove dead files and folders and I always clicked yes.

So, my 1st suggestion for you is to do the same... take a really hard look at what you have on the phone. I am willing to bet most of it is never used. If so, get rid of it, or turn it OFF.