Q: Intermittent Internet Connectivity Issues

I have a MacBook Pro, Mid 2012. I'm running El Capitan, but I was having the same issue with the previous version as well.

Synopsis of the problem is this. Until about 3 weeks ago, everything was working perfectly fine. I suddenly began to have issues. My connection would stop working over the Wifi connection. I changed from the airport to the Dynex wireless router, without fixing the problem. I plug into the ethernet connection, and it works. The wired connection stops working, and the wifi begins to work. I have to alternate between the two to maintain some sort of connection.

What I've tried:

Dynex is completely up to date. Even when the Wifi isn't working, after logging into the router, it says I'm connected to the internet. I have 8.8.8.8 in my DNS.

I've tried to make sure the ethernet and wifi connection are at the top of the list in the system preferences. I've even deleted the ports and reinstalled them to no avail.

I can't seem to figure out what's going on, or how to fix it. Any advise would be appreciated.