If you are worried about being ‘led on” (and rightly so), work out a plan on how you are going to turn things around and/or grow your ex’s feelings for you. The plan should be complete with how you will evaluate if the plan is working and a timeframe in which you are going to implement your plan. At the end of the time period, take stock of where things are and decide if you want to keep trying or walk away.
This way you will not end up trying forever to get back someone who has moved on.