How to choose my goals?

I’m an illustrator and a graphic novelist. In the past, I was mainly an illustrator taking commissions from clients and developing my graphic novels when I had no commission.

Right now, I want to become a graphic novelist full time, because this is my dream and it sounds possible. I want to be free to create my projects, decide the content, aim for success and earn more money.
So I am developing a story and I’m saying no to my illustration clients. Part of me thinks: “Yeah, but I could do both, hiring an assistant, say yes to the clients.” There is a part of me that doesn’t want to let go of my illustration jobs.

I also have a question about how to choose my projects. There is a first graphic novel I want to write and draw, and I already have an idea for the project after that. I want to talk about mental health in my graphic novels. Right now my target market is: women who are 30/40, who have difficulties being a wife, mother and professional at the same time, and want to embrace a creative career. They need a book that is entertaining, that teaches them what is the link between thoughts, emotions and actions, and that will be an inspiration in their lives.

But I also have an opportunity to create a graphic novel about a very famous monument that is being renovated, it’s so famous everyone wants to know about it. I’m thinking: I have access to it, I could create a graphic novel for the children, everyone would like to buy it. The thing is, it’s just an opportunity, it’s not the brand image I want to create in the long term.

What do you think? Thank you for your amazing feedback.