Wireless connection extremely slow now?

(Please keep in mind I'm not tech-savvy at all)

Earlier today, about 2 hours ago, I was surfing the internet when my internet started to slow down to a point I had to wait 2 minutes for a page to load. I was only a few feet away from my router, too, so I ran a few speed tests on speedtest.net, my results were:

Ping: 36 ms, Download Speed: 1.09 Mbps, Upload Speed: 4.25 Mbps

I then wired my computer the the router and got these speeds:

Ping: 26 ms, Download Speed: 22.45 Mbps, Upload Speed: 6.50 Mbps

With my computer right next to the router (wireless) I had a ping of 34 ms, a download speed of 10.05 Mbps, and an upload speed of 5.06 Mbps

I ran a malaware/virus scan, nothing found

No one else is using the same internet as me.

My ISP is Verizon and I pay for a 25 Mbps download speed.

Not sure about the model of my router, though.

Any ways to resolve?

Could it be an interference or a problem with the hardware?