I was driving home from work today when my gauges quit working.I thought it just blew a fuse but about 20 minutes later they started working again.Anyone have any thoughts on what the problem could be?

I forgot to mention that sometimes my headlights start flashing on and off to.

Sounds like a relay on the headlamps.Sometimes on my 84(in the past)when i re-installed the cluster the gauges would quit working if the 2 speed nuts at the bottom of the cluster(in the warning lamp pockets)were not fully tightened?,but thats on my 84 though.

Try removing your gaude cluster & spraying an electrical contact cleaner on the 4 sets of contacts, the 2 in the cluster & the other 2 that plug into the cluster that may help. I had to replace my gauge cluster with one I found on ebay that had very low miles on it, the flimsy circuit board on the back of the cluster is prone to microsopic cracks just from rode vibration and driving a car for years, you can't see them there will still be contact but not 100%, my speedometer used to jump around, and quit then start again, all due to the poor designed circuit board, when I replaced mine all my gauges began to work properly, sadly Chev does not have replacement gauge clusters available anymore. I got the circuit board cracks theory from an electrical engineer friend of mine who designs circuit boards for a living.