Sometimes we have big days. Lots of things happen, all out of the ordinary. Revelatory realizations occur. You couldn't capture it all if you wanted to. Fortunately, you don't have to.
Our brains are never not working. Every single thing you see, hear, think about, or experience in any other way, the brain will process. You don't need to do anything about it; it's automatic.
So let things process. Sure, actively thinking or writing things down may speed up the process, or it may make you more aware of what realizations you come to, but no matter what, you will figure out what happened and where you want to go from there.
If you simply must write about what's on your mind (which is not a bad habit to be in), then pick one subject and focus on it. Toss all your other thoughts onto the back burner and let your brain do what it will. Flip flopping between a million different thoughts doesn't help you get through any one of them any faster.
Writing down your thoughts helps you process them, so process one thought to its end, then move on.