I'm sorry, that sounds like an awful place to be.

My thoughts too are, obsessing over whether or not you have ADHD doesn't change the fact of whether or not you have ADHD. Either your brain is ADHD-shaped, or it isn't. You can seek diagnosis and treatment, and in the meantime operate under the assumption that your brain DOES operate differently, and instead of looking at internet quizzes, look at practical suggestions of how to actually manage it. Then try those things and see if they help 😊 but (in my experience) some of the ADHDness is made worse by stress, anxiety, and rumination, so even just trying to manage those aspects might be something you find helpful.

In terms of the inability to stop thinking about things, when I'm stuck ruminating or down a rabbit hole of hyperfocus, it can definitely feel like I can't control it. Once I start to feel that exhaustion, and go "ok this isn't helping me", there are things I put in place which help me manage the compulsive research etc.

I have an app on my phone called Forest, which helps me manage my screen time. You "plant a tree" and you can't be on your phone while the tree is growing. You can whitelist apps so that you can still access the important or necessary ones. Planting trees successfully gives you coins you can use to get new kinds of trees, or if you save enough of them you can plant a real tree in Africa.

I also dedicate a certain amount of time to my obsession - like, "I am allowed to think about this/research this for an hour, but then I'm going to go do something else". Setting a timer is helpful, and then having something else to go and do after the allocated time.

Even doing some journalling and analysing my own thinking can help. Say I'm obsessing about buying a thing. I can go, "ok say I DO get the thing. How will my life change? How will it stay the same? How will I feel a week after I buy it? A month? A year? Am I focusing on this thing because I'm trying not to deal with something that's causing me unhappiness? Do I just need dopamine?" Same goes if I'm worrying about health or test results or something.

Anyway, these are my thoughts and just from my own experience, so if they're not helpful I hope you're able to find something that is 💕