I would not be able to tell you the most important decision in my life as I just reach half of an avg lifespan. Perhaps, If I make it large the answer would be there in my biography. But so far I have made many dumb choices and many mistakes. And stating that I have learned a lot from them would be a lie. But I can tell you all one thing that I have learned is "Whatever problem you are facing now is temporary."
Time will pass and eventually you've to make a decision. Because Time is such a thing, In case even if you don't want to make a decision it will force you to it. And later down the line you will look back and think "well that was a waste of time". I very well know that there will be moments where you are very indecisive or you will be thinking too much about how to go further on. My advice to you is relax, calm down and weigh your option. chose one and don't look back. Because the worse you can do to yourself is asking "what if"?

regards @inuke
Greetings from India