That was a common problem I would get with my old Belkin router.
What I had to do to get it to fix, is unplug the power from the router, and plug directly from your Modem, to your computer. Most likely your modem is fine, so you will have internet.
From there, plug your router back in. Take the ethernet from the modem and put it back to the router, than from router to the computer.
If you havent tried any of the more simple solutions, try them, like just reseting your router, or reseting the modem. Or a quick unplug from your comp, and put it back in.