Ok, its getting serious now, I need someone's help regarding my internet connection

Hi guys, recently I changed my internet provider because it often happened that my router would just shut down and restart itself which was very annoying and I thought it was because of my provider, but with this shit its even worse. It specifically restarts itself when I play league, not just randomly at any time of the day (it does that too) but it shuts down when I play, sometimes at first couple of days, but last 2 days in every single game I get at least 1 DC which is ruining the game for both me and my teammates. It has gotten to a point where I have caused 2 remakes in 2 days and today icing on the cake I got detected as a leaver since my team lost the game while my router was restarting and now I am expecting a ban or something. Please help!! What is the problem, is it my telephone line or the splitter or the router or some settings or what?? By the way, I hope there is no way I can get a 14 day ban or something can I, because I would be devastated ??