I am so sorry you are going through this. Your post is a heart breaking one.
I do not believe in mlc. Some walk aways are addicts. I think a lot of them are just fair weather friends. It takes bad weather for the LBS to discover it.
He is looking out for himself. He does not want to give you money. He has discarded you. This is entirely about who he is. Not you. He is a selfish, selfish, selfish man incapable of real love. There is nothing else to analyze. I think you are projecting how you would behave and act if the tables were turned. I think we try to come up with explanations (mlc, depression) because we cannot fathom such cruelty amd selfishness and the ability to discard because we are not like that.
Usually, we just fell for a con artist. I was a cover for a high functioning addict and nothing more. Some spouses were uswd for money. I am aqauintances with a narcissitic walkaway wife who admitted to me that she went for her ex because she was getting old and wanted to have a baby. When his business went undwr she left.
Its like trying to understand how a serial killer can kill so ruthlessly. Its in their nature. They are self serving.
I do wish there was some way to obtain justice for you though. Keep reaching out. Dont give up. Can churches help? Going public? Collecting a legal fund? I can only imagine how tired you must be.