A sorry said to the floor and a sorry said to their face are two different apologies.

An apology is partly content and mostly posture. Delivered to your shoes, it tells the other person you want this over with, that you are managing your own discomfort rather than attending to theirs. Looking at somebody while you say it means you are willing to watch what you did register on their face, and that is the part that makes it land as real.

Do the next one in person, upright, and without filling the silence afterwards. Say what you did, not only that you feel bad about it. Then let them answer however they answer.