Sid,
You've got the faster drive but it's only 500 MB, how full is it?
They get fussy as you approach 90%+ capacity.
You can put 8 GB in there which will help.
One thing you can also grab is this
https://fiplab.com/apps/memory-clean-for-mac
Let's you monitor RAM usage and purge memory cache that does not clean itself.
It's free and sits up in the menu bar so you can always see what's going on.
I run it on all my machines and it comes in handy.