Lagging, freezing, driving me nuts

[Prairiepaintbrush]

This phone is getting worse and worse. It pauses when I'm swyping, scrolling, or loading a page. It won't play some videos. All I get is sound with no picture. I'd go to the Verizon store, but my superb intuition tells me they won't help me. My Verizon store used to be great. No more.
I just keep thinking it must be incompatibility issues. I also suspect it might be dueling security software.
How can I find all my security software? And then how can I chose which to keep? And did the phone come with some that will run whether I want it to or not?
I don't really know much. Can anyone offer guidance? My hunch could be totally wrong.

Posted via Android Central App

 

[B. Diddy]

Try booting into Recovery Mode and clearing the system cache partition: Reset: Samsung Galaxy S 4 | T-Mobile Support. You won't erase any personal data, and this can sometimes help by clearing out some of the temporary system junk that can accumulate.