Well, I use a laptop so I'm not sure about exchanging that but my monitor does have a DVI port, along with VGA, HDMI and DP. I've ordered a DVI to HDMI cable to see if it'll work. Thanks for the reply though
The fact that it's a laptop is pretty important, you just said "video card" which implies a video card not a laptop port.
You will not be able to run 144hz on your laptop unless it's a high end one. Sounds like you are using an AMD onboard video, you need to replace the laptop with a real gaming one and check the specs on it to make sure it can run 144hz on the external monitor, or build a desktop, or use a 60hz monitor.