I wonder if LW has financial trouble he's not sharing and that's why he's so angry.

Also, I bet if she followed his suggestion and started a business, he'd find a way to blame her (maybe if the business didn't succeed, or not as fast as he imagined). She could have studied and increased her salary and made a career for herself! Instead of losing that money investing in the business, his money! And if it succeeded, he'd probably still feel resentful because she'd use his money to start it.

At this point I feel like anything she decides will be used as an excuse to keep being angry at her.