I found TDD make programming more fun because it results in less debugging. Debugging can be frustrating and depressing when you get stuck.
I've found ChatGPT makes coding more fun, as I don't get stuck as often on hard problems and it can generate boilerplate quick than I can.
Watch videos by Primeagen on Twitch and YT. He's very high energy. Although successful, He has also struggled with depression, drugs, and ADHD in his past, which might be helpful to you. It's inspiring.
This sounds like vertical slicing (incl bounded contexts), which is my preferred architecture for a monolith. It gives you the flexibility to pivot architecture more easily.
I suggest you look into Evolutionary Architecture, with can help keep vertical slicing
We've gone all-in with SSR+FaaS (aka JAMStack) with multiple projects. You get similar benefits to microservices, but without the complexity. However, hosting can be more expensive under high loads.