Use task manager to check you RAM usage when your computer is slow. It shouldn't matter that you're using an HDD instead of an SSD.
Also, which browser are you using?
it might be the subframes that your browser (i am assuming chrome) is loading to run video/flash/ads in. those things do stupid stuff to browsers and ram usage.
for chrome shift+esc to open the browsers task manager, and close all of the things with "subframe" on it.
That logically means Shantae won't exist, Pokemon won't exist, Digimon won't exist, Jo's Avatar won't exist, Sonic won't exist, Morgan won't exist, a lot of things would Die out... And she wouldn't succeed anyway.
Long term storage (i.e. HDD in this case) is mostly irrelevant for browsing. SSD is not going to help here. I'm assuming you meant 16GB of RAM (16MB would've been alright-ish 20 years ago though!). What matters for browsing is mostly RAM, Network, CPU and GPU (not necessarily in that order).
Your problem is Win10 is a hungry memory hog that will always ask for more, so Microsoft can sell you the next OS on the promise that it will be faster, but they always lie.
I'm having issues also. I did have problems, but my PC never have had any in the last year.
I'm guessing something's happening? Even when I'm not using facebook, that used to consume a ton of RAM, I still experience slight lags. Perhaps youtube might be the culprit, since it had a update...