First solo trip, 6 weeks (Oct 10 – Nov 22): draft Nepal trek + Japan nature itinerary, looking for feedback

Hey peeps,

I have 6 weeks of vacation before I start my new job, and I want to use it for my first-ever solo trip. I'm 29, flying out of Berlin; dates are October 10 to November 22.

What I'm after, in order: new experiences and nature I've never seen before (the stop-and-stare kind), some rest and reset after a heavy year, and meeting nice people along the way. Not really after food tours or monuments. Not against them, just not why I'm going.

I started with Southeast Asia vs Japan, and my research ended up pointing me to Nepal + Japan, since Oct–Nov seems to be prime trekking season in Nepal and Japan gets its autumn colors in November. Here's my rough draft:

Oct 10 – ~Oct 31: Nepal. A few days in Kathmandu to sort permits and adjust, then the Annapurna Circuit (~12–16 days), then a few slow days in Pokhara to recover.

~Nov 1 – Nov 22: Japan, 3 stops. Japanese Alps (Takayama/Kamikochi area) for mountains and fall colors, the Kumano Kodo for a multi-day walk between guesthouses, then Yakushima for the forests before flying home.

Budget: around €3500 total including flights, flexible if something is worth it.

Specific questions:

1. Should I even do Nepal or just do Japan?
2. Would 6 weeks for Japan be too much?
3. Should I combine elsewhere before or after Japan, or stick with Nepal?

Would really appreciate your input, thanks!

P.S. I've been overthinking this for 2 weeks now; please help xD