I agree you need to set boundries with this guy, but the cool thing is, you have the upper hand. He needs you, you don't need him. If he isn't willing to respect your business and your schedule, ditch him. If he is willing to meet your new fees and your schedule, you might as well keep up with working for him. He had his business, which he got rich from, he should be able to understand that you have a business, that you don't work for him except as a favor and you don't need him. Some people just push until they've determined the limit, and then they back off.