Is a routine life achievable?
I see you are having a few completely normal issues that many people in academia face.

Strict routines are good, and for some people they work wonders. But in my experience, the vast majority of people use more dynamic routines, where it doesn't matter, for example, if you've decided to go to bed at 01:00 instead of 21:00 in a particular day, as long as you are getting enough sleep.

As a researcher, get used to the fact that there will always be something to think about or to do. And since you are (unfortunately) not a robot, and your body needs rest to perform well, you have to set up some ground rules, the most important of which should be to make sure you get at least 7-7.5 (preferably 8) hours of sleep every day.
And there are different strategies how to "shut off" your brain in order to fall asleep: ambient music, alcohol, reading, a winding-down routine, etc. I've found that, for me, a good way to fall asleep is to think about floating in nothingness. Gets me snoring in a jiffy.

To help you record ideas, there is a very simple, but very effective, strategy: make sure you always have something near you to write on. Get a notepad (or notebook, or even simple printer paper) for your bedside table, you should have at least one notepad for all of your desks, get a pocket notebook to carry with you (and put it on a reel, so that you don't lose it).
So now, when you get an idea, but can't work on it at the moment, simply write it down in a concise way, and pick it up whenever you have time.
In fact, for ideas you know you won't have time in the foreseeable future to work on, or you are not sure how they fit in with the rest of your work, it may be desirable to keep an electronic list (or list of lists) of ideas, where you can elaborate ideas in greater detail, have references, associate ideas with keywords, sort them by importance, etc.