Please don't go to the ER. Either go to your doctor or one of those urgent care places. This sounds like strep throat. They'll do a quick swab of your throat to confirm, and even if they can't confirm it, you'll be given some antibiotics that will surely help. Trust me I'm a (soon to be) doctor.
Like Pointforward said, just call your PCP or go to a 24-hour clinic. If you go to an ER, they'll laugh at you and give you 1 minute of their time while you wait for 2 hours because a fever isn't an emergency.
Go to a clinic, get some medical attention! Sounds like Flu, Strep or this virus I had that a lot of people go around Houston recently. It starts with a sore throat, then lots of chills and sweats for several days... Keep your fever down! Keep water in a bowl with a wash cloth to keep water on your skin when you get too hot. The evaporation will cool you. Or take a cool shower... and take Ibuprophen to help break the fever. Just keep breaking the fever. This is critical. But really, go see a doc man. It could be treatable.
Your fever spiked after getting out of a hot shower? Why don't you wait a couple of hours and take it again when you are cooled off? I would think a shower would have caused your temperature to spike. There is no way I would go to the ER, I think its a very dramatic suggestion (I also hate hospitals and going to the doctor so take it with a grain of salt). Try a cool shower, ibuprofen and a nap instead. If you are getting worried check out an urgent care center.