you cannto ahve all of that stuff open and excpect quotes to come thru.. get rid of all tabs on cdhrome or browser also.. check task manger to see what exactly is hoggin your resources. in 2018 this shouldn't be an issue.
and the other guy is right.. you need like 16 gigs ram I ahve 32 gigs and am goingot ad another 32 when i getmy next processor. it is also a tech arms race for at home traders..
Your ram used, might be lower, but you could still be getting a hang up, while your OS swaps things out to the swap file, to keep you with spare ram, 8B's will be fine, also check your Swap Files size!! Disable the Indexing Service aswell, I have on mine, if your just watching the chart and not doing anything that could be kicking in, thinking your not using it.
Is it laptop really ? From you describing it may sounds like 5-7 years old model which needs to be upgraded if possible or replaced as soon as possible really. Try to buy new PC with modern CPU and a lot of RAM, you may go even for 16GB at minimum today it seems.