My friend, you are not lost -- you are free. From what I can tell, you have your health, your youth (35 is still young) and you have some savings. If you don't have a mortgage, kids, a spouse, and a job you cannot leave, then you are free. The next step is to see the world. Get a one-way ticket to Chiang Mai and try to stay as long as possible. Learn the language, get a scooter, and talk to people. Live close to the earth, and when you eventually miss home, you will return a different person. Certain places are easier to reboot yourself than others. Pick some place warm and friendly.
Chiang Mai and the rest of Thailand are rather shit at the moment with insane entry requirements. Even if you persevere (and don't get jailed in quarantine hotel) understand that there are no tourists, no expats, no nightlife at the moment and many many failed businesses and ghost town vibes.
"Just learn Thai lol" is not actionable advice either. I say this as someone who has literally done what you suggest in 50+ countries. If he could somehow sneak into New Zealand (not Australia!) I'd strongly recommend that instead at the moment. Buy a van. Hike. So many great treks and places that you usually need to reserve months in advance and far higher likelihood of meaningful interactions.
You can certainly catch a variant or just test positive even if you are fully vaxed and boosted. And frankly it wouldn't surprise me if this is just a way to shakedown tourists.
They decided last week that on the first and fifth days from arrival you must stay in an approved hotel. They don't tell you the results until you are all tucked in, and so you have a rather high chance of ending up in an expensive covid jail.
Next month is a long time away and they are making up new rules as they go as per usual. I admire your optimism and hope you get lucky and enjoy the place as few people will get to experience the islands so empty :)
I will attest to this being quite poor advice. I think the OP is well aware that a cheap exotic vacation and a scooter are not going to fill the gap he feels.
On the other hand, locales like the one recommended are full of first-world young adults testing the theory that a change of location will fix what ails them with markedly mixed results.
Travel can be great, but travel is at best a sort of emotional palliative care for a person in the OPs situation as I understand it.
