Repair requires changed behavior more than improved wording.

The well-crafted apology that changes nothing eventually reads as a technique. What repairs something is different conduct next time, observed over weeks, and words only matter as a statement of intent that the behaviour then confirms or exposes.

After an apology, name one specific thing you will do differently and let that be the actual message. Then do it. If you cannot name anything, the apology was probably about ending the discomfort rather than fixing the problem.