Is there anyway you can relieve you stress in another way? Such as meditation, exercise, talking to a professional, etc. Unfortunately, no one may quite understand what you are going through, my wife for instance believes that I exaggerate things, which might be true, but in my mind and at the time it is a big deal.
Otherwise people dealing with Meltdowns may cause issues that is why I aseed if there was another way to handle it before it gets to that level.
I have found that as the relationship progresses, that their expectations of you change, what might have been cute in the beginning of the relationship might be a lot more troubling to them. I often found myself at the receive end of a complaint when before the behavior seemed to be perfectly acceptable. I feel talking about their expectations as well as how you are feeling and what led up to it might be the way to go.