That sounds like a lot to retire to if you ask me. And $5.5M seems like quite a lot to me. Probably especially if you move back to your home country or almost anywhere else in the world outside Silicon Valley.
Myself, I do have some hobbies but I'd probably go nuts without the structure of having a formal job. If I were you, I'd try and find work that I actually enjoy and find meaningful; you probably don't need to worry about money so much, but if you had a job that covered your expenses, you could let the principle you've already accumulated grow.