Wifi and cellular data both slow

For the past week or so my internet has been really slow, if it even works at all. I can connect to wifi and sometimes to my cellular network, but I lose service all the time or have one bar at most. It doesn't work on any wifi, and all other devices work fine on those networks.

Internet doesn't work on facebook, safari, chrome, snapchat, anything.

For cellular, I don't think it's my carrier because it started happening at the same time the wifi stopped working, and my family (on the same account) haven't had any problems.

I've tried restarting, hard reseting, reseting network settings, restoring my phone and nothing is working. Is this a hardware problem? What can I do?

Thanks