Try uninstalling everything FH related. All folders, add-ons, etc. And I do mean everything. When you reinstall, make sure that you are downloading everything properly, using the right files, etc, etc. In game, try switching your render.
Of course, if it was only one day, it may just have been a bad day for your computer, so to speak. Some days the server just likes to derp out. I would also suggest checking to make sure that your computer is allowing FH and is not throwing up the fire-wall or anything to FH, though it shouldn't be, seeing as you said it was the first time... but yes. I would recommend reinstalling and making sure that you haven't changed any computer settings lately.
