Laptop suddenly running games extremely slow

I've had this laptop since December 2015 so about 2 and a half years now, and it's been an absolute dream up until a couple of months ago. It's been slower than normal for quite a while now, since late June, which is when I believe a windows update happened? And since then, no matter what I do my laptop is just so slow. I used to be able to run Skyrim at 45-50fps (with about 245 mods and a good quality ENB) and it was the same with The Witcher 3(also with a good collection of mods and a lighting mod) and other 'recent' high quality games (Dragon Age Inquisition (with mods), Shadow of Mordor. I got an average of 35FPS in Kingdom Come Deliverance with a few mods).

Now, since late June that FPS has dropped gradually until yesterday, where I can barely play games at all. Skyrim averaging 10-15fps and then crashing, The witcher 3 with 3 fps??? I haven't tried any other games except Metro Last Light where I got 24fps (I used to get 60).

I have tried cleaning my laptop and updating all my drivers, i've tried clearing out my hard drives so I don't have a whole bunch of crap. I've run several AVs and its not a virus (as far as I am aware). Does anyone know what this could be? Is the laptop just old now : (((

The laptop is an MSI Ghost Pro GS60 slim.
Here are my system specs:

Geforce GTX 970M
Intel i7-6700
4gb VRAM
8gb RAM
Thank you : )) I hope I've provided enough info