This is unfortunately all too common. It's hard for someone who isn't an expert in the specific field to separate a smooth grifter from a more typical sales pitch

I hope this is a bug in my phone’s handling of something and not intentional. Until I know otherwise, I’m treating sites where this happens as deliberately hostile for the same reason as always: ads. I use reader mode to escape ads that my ad blockers miss but also to avoid poor design or hard to read fonts and the like. My response is the same as ever: I closed the article.

Nobody forced OP to work 11-14 hour days. Contracting 101 stipulates that you define your hours ahead of time. You come in, you provide your expertise, and you leave at the end of the day. Let the client's junior employees work long hours. Not your problem.

OP brought their own equipment, which is totally fine but "who provides equipment" is also in the contract from the start. OP should have made a list of equipment that the client will require to complete such a project and stipulate a client budget be set aside to cover any shortcomings as they arise.

The contract is where you define when you get paid. "Deposit is XYZ quantity, non-refundable. Contractor will be paid for the upcoming week in advance by X date. Failure to remit payment will halt work."

I understand that the point of this blog piece is that it was a learning experience for OP but this stuff is pretty obvious isn't it? This is pretty much what comes up when you google stuff like "how to get into freelance contracting." I'm shocked and feel bad for OP for letting things get this far. Sadly, they were not ripped off by anyone but themselves.