You apologise when someone bumps into you. You apologise for the state of a kitchen nobody was looking at. You apologise before asking a normal question. Somewhere along the way the word stopped meaning I did harm and started meaning please do not be annoyed with me.
What the reflex was for
Reflexive apology is almost always learned somewhere it was genuinely useful. A house where someone's mood set the weather. A parent who went quiet for days. A classroom where being noticed went badly. In those rooms, apologising first was not weakness; it was a way of getting ahead of trouble, and it worked well enough to become automatic.
The strategy is still running. The room is gone.
A reflex is not a character flaw. It is an old strategy that worked, still running long after the room it was built for.
What it costs now
Constant apology does three quiet things. It tells the other person, over and over, that you expect to be a problem, and people eventually believe what they are repeatedly told. It uses up the word, so when you do need to apologise for something real, the sentence has no weight left in it. And it keeps you slightly braced, all day, against a reaction that in most rooms is not coming.
Not stopping. Replacing.
The advice to just stop apologising fails, because a reflex does not respond to instruction and you end up apologising for apologising. What works better is having something else to say in the same slot, ready before you need it.
Sorry I am late becomes thank you for waiting. Sorry, can I ask something becomes I have a question. Sorry about the mess becomes nothing at all, because nobody was thinking about the mess. The same length of sentence, the same beat in the conversation, without the small self-accusation.
Thank you is the most useful substitution of the set, because it moves the attention from your failure to their kindness, and both of you leave the exchange better off.
Noticing before changing
For a week, do not try to stop. Just count. Most people are startled by the number, and the surprise does more than any resolution: once you can hear yourself saying it, the word stops being automatic, and a word that is no longer automatic can be chosen.