Router problem or my network card problem?

[NDuNiteD]

So I have an Lenovo Y500 and I have some connection issues with my router. I have a modem and router in one thingy and it transmits 2.4GHz and 5.0GHz connections. While my 5.0GHz connection has download speed about 34mbps and upload speed of 5mbps, 2.4GHz one only has max of 8mbps, usually around 5mbps, and the same upload speed of 5mbps. MY computer can't detect the 5.0GHz signal and I am really frustrated because in games like League of Legends I would get like 4000 ping which is unplayble. and CS:GO which i get about like 250 ping. I used my android device as tethering device because it can detect 5.0GHz connection. It worked fine yesterday, and then it stopped working as of today. I tried multiple different apps it still doesnt work. My phone is rooted so the option is open. Anyways, yesterday with the tethered network I got about 50 pings on both games. Glorious. However now I'm back to 2.4GHz network, I'm afraid I will lag again.

 

[NDuNiteD]

BTW, its not just my computer that gets slow connection between 2.4 and 5.0 Its my phone too. it has a huge speed gap. also I can see the router right outside of my door its only like 15 ft away from my room.