Are you maybe just giving too much grace? I do that thing where i basically accept it when someone's behaviour makes sense given their circumstances, but it is still negatively affecting me and eventually they do something a bit too far and can no longer "hide" behind material reality having shaped that behaviour. Then the pent up annoyedness and the valid reaction to that situation gets released at once.

Of course they are not actually hiding or excusing their behaviour, but that's the word that came to me.

tendency to let things stack up until I just orbital nuke my relationships with people

This is a common autism trait. Years of masking and coping with with our sensitivities makes us have a high external annoyance threshold but when we reach that threshold we snap. Often we don't talk about what bothers us because we are bothered by a lot of things. We have been trained to just put up with annoyances because other people don't feel them so acutely.

So when someone does something annoying we don't say anything we just try to find ways of dealing with it because we have been taught that everything that bugs us is our fault. Eventually our inability to cope with annoyances without speaking about them causes us to bring up all the problems at once and often we give up on the relationship all together.

I have this tendency to let things stack up until I just orbital nuke my relationships with people. It’s not my best trait admittedly.

Never thought I'd see something like this in the wild (because it's painfully relatable).

I attribute some of it to attachment issues in my case, that some part of me wants to distance myself because of anxiety no matter how it's going, so if I also have an excuse to distance myself, my brain latches onto that hard. But sometimes I do have legit issues too. Sometimes even, I'm flummoxed that others are seemingly ignoring issues that I consider a problem and are sticking around regardless.

I guess the healthy thing would be to bring things up immediately and try to resolve them before resentment builds. But sometimes that's hard to do in the moment.