OS(C) drive Filling Up in Dell Vostro

So it's been a Year using my Dell Vostro 3500,

Machine Specs:

Processor: i5 11th Gen

Ram: 8gb

1TB HDD + 256GB SSD (Operating system is in C)

Operating System: Windows 10 Home Single Language

When I bought it back in 2021 Everything was working fine, No filling up of spaces which is obvious as it was new. I downloaded few games specifically GTA-V and since then C drive started filling up unnecessarily. It was new so I had plenty of space in my so It was not a problem back then but now It is getting serious as I am running out of space in C. Initially around 120-140Gb was free but now every week around 10Gb gets filled up.

What I did which I think might cause these problems? 

I installed few games. Also I created a partition of my HDD into two parts and something very weird happened whenever I try to download files in my D(HDD) drives it says permission denied, It seems my own system is using me as a stranger usually I am the admin right? 

Since I am posting my question here so here are the few things I did to solve this problem on my own but it is not solved, problem is deep rooted

-cleaned the Temp, prefetch, %temp% folders uninstalled unnecessary programs like GTA V. to free up space but to my surprise the space was not increased rather it was decreased around 200mb was decreased. but when I restarted the laptop space was increased by 1GB.

Below is my Disk management.

I want to fix this ASAP. I want to dual boot my laptop to ubuntu and I need to fix this first.