If you live in a major city, you might try looking for local writer’s groups. I go to one at a coffee shop near me, same time each week. The person running the cafe gives a prompt and after a couple hours, people can share what they’re working on, but usually no one does. It’s just a quiet space to practice writing with relaxing music in the background. No socialization expected or required. I’m not a fan of caffeine, so I usually get a hibiscus tea and write a poem based on the prompt. Very low key.

Hi there! I‘m not good at pointing out patterns or solutions instantaneously so I‘ll just provide you with the stuff I do. I don’t have adhd to my knowledge but I do struggle with schedules at times.

So, what I do as hobbies to feel better:

• take a walk along a specific route, either with someone or with music on my ears
• if I‘m able to walk many days in succession, I attempt light running, which sometimes works and can lead to a hobby
• if I‘m in pain often, I rather go swimming in a swimming hall. Repetitive swimming motions make my brain go in trance mode. Thats really cool. The secret is to swim slow enough to not have to stop.
• If I don’t feel like going out at all, I try to do light yoga, I listen to yoga with adrian on youtube.
• when I need to see humans (which I try to avoid actively) I do dnd campaigns irregularly or visit a games workshop.

As you can see, I‘m totally okay alone and try not to be with people as we tend to hurt eachother. If I need to, I select them individually. I don’t do groups, ever.

I hope this helps.

• Gardening: it requires little things but regular attention, and you get food and pretty flowers out of it. If you can’t do it at home you can try guerilla gardening somewhere in your neighborhood.
• Astronomy/radio astronomy: nothing more regular and scheduled than the stars.
• Cycling (if you live somewhere where it’s safe to cycle)
• Swimming/Trekking
• Do you know the youtube channel Save it for parts? Maybe it can give you some inspiration, he also has ADHD and he’s always jumping between different projects.

If you have money to spend here are some ideas:

• multicopters flight in field of vision or FPV
• RC cars, there may be some RC race tracks around big cities
• if you have some sea or lake nearby, windsurfing might be good idea
• photography

More cheap ones

• find some hackerspace or maker groups, they usually understand that someone needs less social interaction, and you can learn to build stuff
• bird watching
• ingress mobile game (or any other made by niantic)

Have you tried disc golf? You can pick up everything you need for $20. Virtually no interaction if you play by yourself. Other disc golfers are generally super chill. It’s fun to work on your technique and try to improve your score.

The needs you are describing are needs I have as well. I meet them by going for walks in the park. I live near a big park though where I can walk for like an hour or more at a time if I want. You might look into hiking trails in your area. I also bring my dog on walks, both because he needs it ofc, but also because if he wants to greet another dog then it forces a social interaction, but one where it’s normally 1-on-1 and where there is an obvious topic of conversation. Plus being outdoors is super good for mental health.

It’s the wrong time of year to really seize it, but my ebike is the sole reason I leave the house daily. Most days it’s less than a 3 mile round trip for a few energy drinks, but I’ve done 90+ miles in a day and regularly ride a 19 mile loop over dubbed my “Kessel Run”.

If you like video games Pokemon Go still works and can be a good motivation to go outside and walk a bit, it’s also something you can do alone or with a friend

have you considered taking a class? it provides social interaction, which I’m gathering you want a little of, stimulation, education, but keeps interactions fairly structured and predictable.