My career and personal coaching clients have found this advice helpful: Take a low-risk action. You'll more likely benefit from that than from additional rumination. Examples:
1. Wondering whether you're ready to start dating again? Hang out once at a place you're likely to meet your Mr. or Ms Right and see how you feel. You can always say no to an overture.
2. Not sure what career is right? Read the intro to many careers in the Occupational Outlook Handbook, U.S. News & World Report's Best Careers or Cool Careers for Dummies. (Bias alert: I wrote the latter two.) And/or just google the name of the career and the word "careers," for example, geologist careers.
3. Not sure you'd be better off if you stopped smoking? Abstain for a day or three. You can always go back to killing yourself.