When does an apology stop meaning anything?

He’ll say sorry every time—like straight after, proper remorseful tone and everything. Last week it was about forgetting my mum’s birthday dinner (again). He said he felt awful, bought flowers the next day, all that. But then he did the exact same thing two weekends later with my sister’s engagement get-together. Same excuse too—‘lost track of time’—which, come on. We’ve been together six years and this pattern’s been going years now. Apologise, repeat, apologise. It’s not just family stuff either—leaving me to sort all the bills, promising to help with the dog walk and then vanishing into his gaming chair like it’s a national sport. The weird thing is, I think he means it when he says sorry. But does that even matter if nothing changes? Mam keeps saying ‘he’s a good man at heart, just needs patience’ but I’m starting to feel a bit hollow every time those words come out. I don’t want to be that person who’s always quietly pissed off, hiding behind a polite smile. At what point do you stop believing the words and start believing the actions—repeated ones? I just feel stuck because walking away feels dramatic but staying feels like slow suffocation you don’t notice 'til your chest aches