1. You don't take right decision. You take decision and then make it right.
2. Write it down. Our brains tends to have circular/non-linear thoughts process. Write down your feelings, goals, ambitions, dreams, pros, cons and every little things that goes around your decision. We human are very visually oriented animals. It is easy for us to analyze rationally when things are visible. In this regards, try to bring your thoughts on a paper.
3. It should be your decision. I can't emphasis this point enough. You should be prepared to face whatever comes on your way with the decision. As Frank Zappa said -- "If you end up with a boring miserable life because you listened to your mom, your dad, your teacher, your priest or some guy on the television telling you how to do your shit, then you deserve it."