HELP!! Internet problem.A serious one.

So i was playing cod 3 in my ps4 and i had a strict nat type.So i wanted to make it open so i can play with my friends.I saw a couple of videos then i logged on to my modem and tried to port forward so it will go open. Nothing worked so i disabled those apps i created. Then after a while i couldnt connect to the internet from my ps4(lan cable) but laptop and mobile phone were just fine.Couldnt fix it so i connected ps4 with wifi.It worked fine and i had nat type 2 and on cod it was open!

BUT the next day my father went down to his pc (lan cable) and there wasnt any internet. Same from devices that used the device that brings the wifi signal down the house.

We called our internet provider and told us it has nothing to do with them is an "internal problem"

I dont know what to do please help.

Thanks in advance

There's a reset button on the back of the router, press it.