Tension and discomfort due to stress?

I'm not sure if this fits in here but maybe someone has a similar problem. I was promoted to group leader a year ago and now have 10 employees under my responsibility. We are in the project business which is very dynamic. Working days of 12 to 14 hours are often normal. The only problem is that I seem to stress myself out so much when there's a lot going on or projects aren't running that I seem to cramp up and get aches and pains. Does anyone else have this? A Teams meeting or a stupid email is often enough. Could it also be that it's just too much for me? The problem is that at first I thought it might be the coffee, but even without coffee I'm very hippy and distracted. What could help?