Hi, I'd like to help you with your problem.
You are in a very difficult position. I agree with you, you need to decide what you want before you make a decision. Since you have had relationships with both men and understand what you felt with both, it is not a question of either man making you happy. It boils down to the question of what you want.
I would highly recommend you seek out therapy. This is a decision that you do not want to make lightly. But besides that, it is very important to find out what is driving your inability to feel settled in either relationship. It is easy to feel that obvious things in the relationships (such as money and occupation) would be important, however, they are not. What you feel when you are in these relationships, your background and view of how a relationship should be and any other life experiences you have had will affect your feelings about commitment and relationships and this is what you need to have resolved before you can decide what to do.
You pointed out that you are interested in finding an answer quickly. I can understand your urgency. However, I feel it is important that you take a step back and go slowly with this problem. The old adage that if it is worth it, it will wait is true. These gentlemen and their feelings for you will still be there after you resolve your feelings about the relationships. If they are not, then you will have your answer about whether or not they were worth the risk.
A couple of good books to get you started are Too Good to Leave, Too Bad to Stay: A Step-by-Step Guide to Help You Decide Whether to Stay In or Get Out of Your Relationship by Mira Kirshenbaum and The Relationship Handbook by George S. Pransky. You can find these on Amazon.com or your local library might have them.
I hope this has helped you,