Sounds like the middle man you worked with was an asshole. What's the lesson there? Don't work with that company/person. And think about what signs you can look

Sounds like the middle man you worked with was an asshole. What's the lesson there? Don't work with that company/person. And think about what signs you can look for in future partners that can tell you they are a similar sort of asshole. The "true client" proves there's business for you to get which will pay you what you want to be paid. Go out and find the customers. That's really what it comes down to.