Big decisions are hard enough, do not suffer them alone. Obviously seek out those who are knowledgeable about the situation, ask those close to you and those with valuable opinions.
Also seek out the opinions of those you trust but who are not close to the situation. Distance may bring clarity and a bigger-picture mentality into your decision making process. The counsel of others can reveal blind spots or weaknesses in your current plan.
But you cannot be afraid of where all that counsel points. If an overwhelming majority advises you in a direction you're not comfortable with, investigate further and take your time. They may be right, they may be wrong. The full ramifications of a decision are only seen after the fact, but you can do as much as possible before making one by seeking as much wise counsel as possible.