There will be challenges but I finally feel like I‘ve created a solid foundation I can build upon. Therefore I will continue to strive and be disciplined.
This is the most important thing, believe in yourself and push yourself where appropriate, but having the right routines and mindset is an important foundation to build on.
Congrats on the promotion, when I was first promoted into a management position I went through similar for a while, though it was a good while ago now, I still remember the issues I had well.
I don't know if you have been promoted to a management position, but two things I had to learn but helped massively was learning to delegate without feeling guilty about it, that took some time. And also overcoming a bit of imposter syndrome where it's all new and I felt like I'd fluked my way into something I might not be able to handle. Which was not the case, and it won't be with you either, you'll have gotten it on merit (unless there was nepotism or bribery involved

).
I've spent over a decade in management since and now manage a whole department, and over that time situations I found really difficult once, I feel quite calm tackling now. There are situations that are never nice, disciplinaries and letting people go, but as long as I'm always aiming to be fair and feel the outcomes are deserved I'm very much at ease with them these days, though they'll never become nice situations to deal with.
But with any new job, especially one that requires new skills and experience you don't yet have, there can be issues that connect to confidence which will naturally improve and be overcome with time as you gain the experience you need. Hopefully your in a workplace where you can get support and assistance when needed, it also helped me to have someone more experienced in a similar role I could reach out to when I needed advice on certain situations and also having a manager above me who was supportive.
You're own mental and physical health is no less important after a promotion than it was before a promotion. It sounds like you're on the right track and looking after yourself. Always make time for yourself, take breaks from your normal routine and work, and have moments to slow down and let go of stress as best you can.