Promote to warehouse manage for a week now. Now keep having ruminating or think about work .

Before I get promote, I was a team lead for 7 year. I love the job and when my boss go on vacation I do his job also. Now that my boss got promote to operation manage, he promote me to take his position. Now I feel that I regret taking position because I keep thinking about work or thing that not happen yet but my mind keep wondering all the time. Any advise.