Improve my laptop for gaming? What should i do

Yes, i heard it before, a laptop isnt the best choice to game on. Im but a simple student who got a laptop for school and dont have the extra funds to buy an awesome PC. (Its on my to do list though)

My laptop has following stuff:

Cpu: Intel core i7-4510 @2.00GHz (i see it 4 times in the processor list?)
Disk: a 800gb disk (HDD)
Display drivers: Inter(R) HD Graphics Family & Nvidia GeForece 840M
RAM: 8 GB
Usage: around 12 hours a day, pretty much non-stop
Age: Around Spring 2016 (is it that old already?.. dahm they grow so fast)

i had the impression this wasnt a bad setup but im not an expert on this.

History of my Laptop:
It went well in the beginning. I could play LoL, warframe, Tera etc with not much troubles that i noticed off.
But now i cant play any games full screen anymore before it starts laggin or flashin all over the place. I didnt rly care at the start is just started playin everything windowed.
Also i get really high ms sometimes at the most random times. (this could also be my network though but it happens quite a lot on different networks), or i would just not be able to connect to any wifi thing for 5 min straight till i reboot.

But now i wanted to play Dark Souls 3 and i read something bout the system requirements online and i thought i could manage. But as soon as i started the game it said that i had problems with my fps and couldnt play online (not much of a problem) but i keep lagging like ive a low frame rate. Graphics are already on Low.

Is there something i can do to change this? Or is my laptop just worn out and old?
Any tips for this laptop-noob? :)

840m was already a low end GPU when it released and no, you cannot change anything to help it

Keep the number of Startup apps to a minimum. Laptops (and pre-built PCs) have a penchant for having so much junk starting up.

You can download more RAM, that always helped me.

Can't do much here, and it's true for every laptop...You are tied to your gpu performance which can't be changed :/

It's all depends on the gpu your laptop comes with, some have the power of a desktop gtx970 ( gtx1060M ) or even higher...but the price goes up accordingly,

All you can do is lower graphic settings and resolution and as mentioned before close all unnecessary apps.

You should also make sure that your game is using the nvidia gpu and not the intel build in gpu. You can do this through nvidia panel.

It's should run like this :

https://www.youtube.com/watch?v=_W0IlE5NyrM

If your laptop is like: "I have been running this game on 60fps but I won't do it now cuz f*** you" - I would format it and reinstall whole OS. It doesn't take really big amounts of time and most of people hate doing it idk, why.

@lollipopoffury: No need to bump old threads

@MonsieurX: Sorry. I needed that three posts and I didn't play wide range of games and I don't really know anything about hardware. so I had to make quite deep searches. I thought that I could help and didn't notice, how old this is XD