I still get butterfiles from time-to-time. That's right, after doing this for 25+ years, I admit there's times I still get butterflies!
NCASA has it exactly right: slow down!!! It's a marathon, not a sprint. And it ain't nothin' 'till you call it! Once you think you've slowed down on your timing enough, then slow down a bit more.
Most of all: have fun!!!!