Quote: she demanded more and more of my attention. Demanded it! From a submissive. I accused her several times of topping from the bottom but she always put it down to her anxiety issues.
Re-read that sentence several times and see if you can tell me where blame factors in. Anxiety IS an issue. An unhealthy and destructive one. This accusation also sounds like an excuse. Regardless of wherever they were actually being demanding or not (I'd need to know what they said to determine that. Even then people have a horrible habit of saying things they don't mean).
When someone else gets less attention (time wise) they can feel left out. When people complain about that and harp on about wanting to spend time together that's not "topping from the bottom". That's a fear of you not being there. The absence that you put in yourself validates that fear. I'm not just talking about your eventual break up. I'm talking about the time before that where you most likely became more and more distant. Perhaps even evasive and difficult on purpose.
People can sound demanding. Perhaps even be so. But if you're going "I blame thee" without saying anything YOU did to factor in as to why things went downhill then that's just being all blame and no responsibility. Were they actually being demanding or pushing for compromise and botching it up? Were they actually "topping from the bottom" (as if that's an excuse) or so afraid you wouldn't be there that they can't even control their fear, let alone you? Again I refer to "pre-breakup".
Even a sub is going to try and "take charge" if they feel powerless. But if they feel powerless then there's a reason for that. What is that reason? And do you even know yourself? I suppose this is a question of wherever you were there as much as you could have been in the first place or if you were more focused on others. Even if it's fine for you to be with others more it could have still resulted in the sub only being engaged with every week or so instead of more "daily". It's kind of hard to pinpoint a "balanced" time across the board but basically it's a matter of "consistent presence". Doea mean "be there and do enough". Doesn't mean "At all times".
"Consistent presence" (how often, how long, etc) should always be one of the higher priority topics to be discussed. AFTER that it's a matter of what to do in that time and how to make the most of it. Sure, you can avoid someone if they're being demanding. But what if that is WHY they're being demanding? (and I highly suspect that was never stated). This puts you in a loop.