A meet is not a workout
Iron Maidens was a glorious day of heavy metal and boundless energy... But the following day (or three), you might have felt like you were hit by a truck.
How can that be? All you did were 9 lifts - seems like a lot less work than a long training session or a CrossFit class.
But competing in a meet is more taxing than a workout. It is the culmination of hard training, and your emotional commitment is at its highest. While you may have gone for heavy singles as part of your training, maxing on three lifts in a competition brings out a different level of capacity that you might not find on any given day in the gym.
It's called Meet Magic.
The adrenaline, camaraderie, audience cheers, personal goals, Beyoncé... these all feed into a performance of your strength: everything is heightened. Some of you may have hit numbers that shocked you. And some of you may have put all your guts into making a lift, only to fail it. In both cases, you pushed yourself harder than you probably thought you could, which is a big strain physically and mentally.
It's also a long process.
You have to sustain the ability to perform at your highest intensity in a punctuated fashion. In other words, you need to be able to psych yourself up for a big effort 9 times over 4 or 5 hours. The cycle of warming up your body and mentally preparing to push yourself as hard as possible, doing it, and then coming down only to repeat it two more times is fatiguing.
After all that, it's normal to feel like a 45 lbs bar weighs 100 lbs, or you can't get enough sleep, or your usual amount of coffee isn't making you alert. The best thing to do is eat well, take a little rest, and then ramp your volume back up over a few days.
Respect the fact that you gave it your all and give yourself a chance to recover.