Welcome to PC!
Yes. I've been dx'd with both. BP first. There's never been any doubt on that one. The ADD one came later, and I was not quick to believe. Like you, I didn't particularly see myself reflected in what I understood it to be (which was a pretty limited profile.) Then I learned more. Now I can see it. There is quite a bit of crossover in symptoms. Sometimes one dx will cover. Other times there's symptomatically more to account for than one dx will cover.

It's curious that having the AD without a mood stabilizer (apparently) didn't send you manic-y. Unless I misunderstand. That would certainly cause me to wonder if there was a mis-dx. Were the 8 meds all anti-depressants? (The ones preceding the BP dx/ Seroquel). It might well be that your symptoms are all accounted for by ADD. It's worth looking into. I'd think one of the things to think about would be symptomatic spans. That is to say, have your symptoms had a cyclical sort of pattern like BP, or is it pretty much just a day in day out consistent pattern?