Hello I'm not really computer savvy when it comes to routers and such but this problem has been doing my head in for quite a while now.. I was hoping someone who is knowledgeable on this subject might be able to help or maybe point me in the right direction(sorry if I posted this in the wrong place).

Okay so really quickly from the beginning.. I play an MMO called Elder Scrolls Online on PC. I've played it for almost 3 years and my latency has always been at a stable 200 ping. In the past few months however, it now stays at a constant 350+ ping. I referred to the games manual on latency issues and it suggested I open some ports. I've tried port forwarding the requested ports and checking to see if they're Open at portchecktool.com but it gives me an error saying 'Connection timed out'. When I tried disabling the firewall/windows defender the error then switched to 'Connection refused'. Sometimes port 80 would say it's Open but the rest of the ports would still give me 'Conneciton timed out'.

My ISP is Slingshot and I am on VDSL. The router is a TP-Link TD-W9970 V1.0. OS is windows 10.

If there is anything more you'd like to know just ask and I'll be happy to give as much information as I can.. thanks