EndeavourOS (Linux distro) is quite laggy

I have a laptop with EndeavourOS on it. It has a Core i3-4405U (4) 1,6Ghz, and it's sometimes lagging, e.g. if I start a program like Firefox or a game like Minecraft. It just starts lagging so much that even the mouse is lagging, and nothing works anymore. The fan is speeding up, and my HDD is starting to spin like crazy. Is there anything I can do to fix it?

[zuna@zuna-80hw ~]$ LC_ALL=C free -g
               total        used        free      shared  buff/cache   available
Mem:               3           2           0           0           0           0
Swap:              0           0           0