Brain gets 'stuck'

I'm not diagnosed but am waiting to be tested for ADHD-PI, which seems like it might be the answer to a decades long question. I wonder if any of you who are diagnosed have had this problem?

If I spend too much time on one subject or activity, my brain just will not let it go. If I listen to the same song or CD too many times in the space of a few days, or watch one too many episodes of the same show, or spend too long reading about a subject my brain gets locked into that mode and I cannot think about anything else. Even if I manage to do something else I'm aware of it at the back of my mind, like I've left a light on in another room. It will keep me up at night replaying songs or scenes, or endlessly ruminating over facts or stories I read- sometimes even just certain phrases or a handful of notes will get stuck. It leaves me feeling anxious and agitated like it's rubbing my brain raw in spots. I have to actively avoid the trigger for a few days to get it to calm down, and after that I avoid it for a bit longer to keep it from reoccurring.

Right now it's cleaning. I have been doing some serious spring cleaning the last few days but my brain has caught on and now I can't shut it off. I cleaned for six or seven hours straight and I'm exhausted but I can't stop! My brain's like, oh you're too tired to clean so let's obsessively plot out future projects and make cleaning charts and lists of supplies and oh my god let's redecorate everything too so let's get some paint colors rolling around in here too, great!! and I just want to wind down. It's a great thing on one hand because our house really desperately needs some fixing up and I really love doing it but it would be nice if I could do things without getting so caught up in it.

I feel very confident that it is not hypomania. It is really obviously triggered by a single activity and does not come with impulsivity, high energy or abnormal moods. It's generally just the flavor of the week that I am preoccupied with. I've been like this most of my life, very prone to waves of obsession- I had a new hobby every other week in elementary and middle school. It makes it difficult to be consistent with anything because often I'm either vaguely disinterested or all in, full steam ahead until I burn out and then I can't make myself do anything for awhile, until something catches and I get obsessive again and it just repeats over and over. It's the worst.

Does anyone else experience this?

I don't know if it is related but I have a million plans going on inside my head. And I have an incredibly hard time starting. But if I start it is possible I cannot stop. When I was a kid, cleaning my room was a nightmare because I didn't feel it was done unless I took literally everything out and put it in the right place. It totally drained me.

I usually call this " Brain Lock " .