There was a line at the beginning of Bojack Horseman (season 2 I think) that I always think about: “It gets easier every day, the hard part is doing it every day.”
Try to find ways to work exercise into your routine. And more importantly, think about how to still do it when days are tough because you get busy.
Edit 1: I stopped taking meds when I was young back in the Ritalin days. I don’t think I ever quite fit in, but I’ve found that daily exercise helps me channel my little bit of attention enough to sit through meetings long enough to do the parts of my job I enjoy.
Edit 2: Also, Google “Pomodoro Method”. It’s pretty much the only thing I do with my smart watch, and it’s fantastic.