It's very important you really do listen to this. You are still young yet and need to learn more about boundaries and paying attention to how you may "need" too much when it comes to other people. If you take up "his" life with YOUR life, he will need to leave you for his own mental health.

I struggle with both anxiety and depression myself as I have ptsd. My husband can be too much for me as he tends to take over my space too much. Truth is I like it when he is not around because when he IS around he tends to take over my space. Honestly, be glad for this friend of his that gives him some space where he can see himself as being creative and starting a business of some kind. If you start getting jealous of that then it's a red flag you are probably being selfish and need to rein yourself back and give him space. A flower can't grow if you stand over it constantly casting shade on it so it doesn't get enough sunlight.