Check battery heath status.

You need to do some basic optimizations. You can find easily on youtube.

You can try using these steps to minimize lagging problem-1.free space atleast 3 gb in phone.2.do not run heavy applications like gaming applications.3.optimize your phone to 100% in device maintaince.4.uninstall useless apps5.update to latest versi...

Are you using any third party application like video recoder or something else?

Bro you absolutely are right.