Maybe you are looking at the big picture and comparing it to your situation now which may be very different - take small steps, so run ONE length of the block when you next walk the dog. That is all and it will be a lot more than you have done.
Then just keep it consistent and the results will accumulate, and so will the desire to run further etc.
And, most importantly, any negative 'hold' on your mind will lose its power as you will have taken that all important first step as you will then discover that you are in control.