That did the trick!

Thanks for taking the time to help me out! I'm still trying to learn my way around linux ^^

A little update about this situation.

I've contacted my ISP and i can't seem to switch out the modem. They sent me some firmware updates, which also didn't help. The solution they offered me was, buying an external WiFi adapter or hookup a router to the modem. Both options are out of the question for me.

But now something I can't put my head around. As said previously most of times i get speed under 1 Mbit/s, but as soon I transfer files over to the pi by SFTP i get much better speeds (atleast 5 Mbit/s stable). This proves there is nothing wrong with the signal or antenna in my case.

@rascas Thank you! Kodi is now working.

Run sudo apt-get update && apt-get -y dist-upgrade && apt-get install pulseaudio

I did earlier today when I upgraded to Kodi 17.1, but I used the keyboard to get into Kodi's input, peripherals settings and was able to map my Xbox360 controller there in the KODI UI and it's working fine.

@spruce_m00se I never tried the ds4drv, it can be the problem in Kodi.
Network connectivity is done in RetroPie scripts, it is system wide. I saw some people with problems in their networks and they fixed it changing DNSs. But again, only with the Kodi logs with debug on, we can know for sure.

Anyone who is looking for clearing the KODI cache could refer to the following article:
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