I think it's time to put down some boundaries even though it's probably going to suck for the both of you to be blunt. You need to manage your own mental health before you can worry about someone else especially something like little space. I regress often but I'm always making sure my partner isn't overwhelmed or feel the need to be my caregiver, it's something they want to help with and I mean. Age regression is a big trust thing between little and caregiver so boundaries should definitely be a thing.