Is there something you wish to achieve that causes you to say, "Only if ..."?  Forget "only if."  That won't get you where you want to go.  Instead ask yourself, "what is one small step in the right direction?"  Then, take that small step.  The biggest step is the first one.  The first step cracks the barrier of seeming impossibility.  The first step builds momentum. 

Newton's First Law of Motion states that, "An object in motion tends to stay in motion, and an object at rest tends to stay at rest unless acted upon by a force."  Let your burning desire be that force.  Don't stay at rest.  That won't get you anywhere.  When you are hungry, do you have enough energy to walk to the refridgerator, or will you sit in your comfy chair and starve to death?  Your burning desire is a hunger.  Don't sit there.  The success sandwich won't make itself. Move.

Stop what you are doing for a moment and write down on a piece of paper what you desire the most - something positive.  Take a moment and do it now.  Now, look at what you wrote on the paper.  What are you going to do today to get you closer to achieving that desire?  Rome wasn't built in a day.  A journey of a thousand miles begins with a single step.  Put that peice of paper in your purse or wallet and look at it every morning and ask yourself, "what will I do today to get closer to this?"

It's not enough to ask the question.  You must act.  Don't be deterred.  You're no longer the person that doubts your ability to achieve this goal.  You are the person that will achieve this goal.  There is a burning desire in your heart and soul - stronger than any hunger - driving you to act.  You will not be stopped.  You will embrace setbacks, adjust, and take another step.  You are strong.  You are bold.  Audentes Fortuna iuvat = Fortune favors the bold.