Late Update Tomorrow

Hi guys, I don't want to alarm you but my macOS is having a problem again ^^;

Last month, I formatted my HDD and everything seems to go well. But ever since last night, my macOS is lagging like crazy--like really bad. Safari is not responding and my RenPy even showed blank sheets when I tried to open the code scripts. I almost freaked out, thinking they're suddenly gone or something but turns out my macOS is lagging so bad, the blank sheets are RenPy loading to open the scripts ^^; 

The strange thing is, my Windows (which is also installed on my macbook) is doing just fine. So why is it only my macOS Sierra lagging? @@

That's why, I've decided to bring my laptop again to the service store tomorrow. So please excuse me if I post the weekly update late tomorrow ><

I might have to reinstall the macOS again or replace my HDD with SDD :S 

Hoping for the best
Xoxo

SweetChiel

P.S. For those who is wondering why did I install both Windows and MacOS: because I've been using paint tool SAI and it cannot be used on macOS. It's the only software I use to draw without the risk of crashing.

UPDATE:
I've found the reason why my laptop is lagging: the Safari Browser.
The Safari seems to be... corrupted? I mean, it keeps refreshing everytime I opened youtube and now, it becomes so heavy, it burns through my RAM? ^^; I'm not sure why and how it became like this, but as soon as I used firefox as default browser, the lagging become much better. Much more tolerable. I might don't need to go out tomorrow!