The way you frame your decision at the outset can make all the difference.
State your decision problems carefully, acknowledge their complexity and avoid unwarranted assumptions and option-limiting prejudices.
Recognize what happened and how you feel. Suppressing your emotions will get you nowhere. It’s important to first focus on how you feel.
You can also journal your emotions or speak with a close confidante. Or you can go to therapy, of you think it's right for you.