There’s no reason to worry about something you’re already going to do. ~ a friend’s therapist

Make up your mind. Then what?
Are you going to dwell on it,
reassess the decision? Mull over options?
Are you experiencing guilt knowing
the decision is not your best choice,
your wisest action, who you want to be?
What are your real options?
You can prepare to do it as well as you can,
accept it as inevitable, think what you might learn,
look for efficiency and purposefulness
to achieve it, reassess the decision
and choose more wisely.
Just don’t worry. Don’t give way to anxiety,
dwell on expected difficulties or troubles.
Like Yoda would tell you, Do. Or do not.
There is no try.