Hurm. I can't really help with the fear aspect, but for your other issue, It sounds like there could be some jealousy problems. Maybe he's worried that you're going to get caught up in the random hookup culture of some DZs.
Have you reassured him that your jumping with other instructors and more experienced jumpers has nothing to do with him, and that you are only trying to be the best and safest that you can be?
Maybe ask him that if (for example) he were going to take Nascar racing lessons, wouldn't he want to learn from the absolute most experienced drivers available to teach him?