Best solution - Apply themal paste(Not so practical in the lockdown situation, because of all the shop clousures. You can order it online but be careful as you might screw up something when opening your laptop)
2nd - Delete the package called performance-tweaks and install powersaving-tweaks.
Install packages like auto-cpufreq and thermald
Get a kernel not aimed at performance. linux-zen is pointed for desktop users which you arent. Install the linux-lts or linux kernel.
Give the following a read :-
Seeing your inxi, you are rocking a 2nd generation dual core CPU. KDE wouldn’t be a good choice.