I have helped a man I loved before. It caused me a lot of stress but I did it anyway out of love.
While supporting your ex-husband is naturally up to you or the terms set forth in your divorce agreement, there comes a time when assuming he is capable of doing so, a man needs to hold his own.
We as people are designed to need each other. It is also good to help those in need. If he needs the help go ahead and help him until he gets on his feet. If he is disabled and cannot live without the income from you that is a different story in itself. My mom was disabled and I found that from time to time my dad helped her throughout their lives after the alimony stopped.
As far as dating someone else who can carry his own weight, that would be a good thing to do when you are ready to do so. I cannot say there is a timeline for when you will be ready to do anything. But when the time is right, you will know.
As for now, think of what is important for you and your family.