Resist knee-jerk decisions. Unless the decision must be made now, give yourself time to weigh the options. Do set a time limit, though -- "I’ll decide within three days whether to make that investment" -- so you don’t drag it out unnecessarily.
Temper emotion with clear thinking. Remind yourself that, while it is normal to feel an initial flood of panic, confusion and frustration, you don’t have to be ruled by wild emotion. Take some deep breaths, and trust that these feelings will subside, giving your rational mind a chance to think things through.
Do a cost-benefit analysis. On a piece of paper, make two columns headed Choice A and Choice B... or Yes, I will and No, I won’t. In each column, list all the reasons that support that choice, considering the likely outcomes. For instance, if you’re contemplating divorce, the No column might include "Money will be tight" and "The kids will be distressed"... the Yes column might include "Less arguing every day" and "Freedom to be myself." Next, rate each entry’s importance from zero (unimportant) to 10 (vitally important). Then add up the points in each column. Seeing which column scores higher may make the right choice clear.
Test your calculations against your gut reaction. Sometimes a choice that seems rational on the surface simply feels wrong deep down inside. If you find yourself fighting the results of your cost-benefit analysis, perhaps your lists and ratings do not accurately reflect your true values, goals, needs and desires. Listen for your inner voice and trust your intuition to guide you toward a clearer understanding of yourself.
Get feedback from a mature and insightful friend. Ask her to just listen at first as you outline your situation -- speaking aloud helps clarify your thinking. Then ask, "What would you do if you were in my shoes?" and consider whether the advice feels pertinent to your life (not just hers). Lastly, have her play devil’s advocate while you defend each of your options -- as you counter her arguments, your own position will become clearer.
Once you’ve made your decision, don’t second-guess yourself. Accept that taking one road always means letting go of the possibilities from the other path. Trust that even outcomes that don’t seem desirable now can turn out to be in your favor in the long run.