Thank you Jane, NyCindie, and fuchka for your responses. I really appreciate them!
I don't feel like thinking about that lack of energy stuff too much right now, but I want to write about one realisation I had.
I notice that it is sometimes hard to express my needs not really because I fear my partner's reaction, but because when I am in that bad place, I feel any
reaction is difficult to take. Seeing the disappointment is horrible. But to have my partner say "it's okay, it's no big deal, I still love you" feels like something so undeserved. Even though, rationally, I think that is the coolest response to give, in that moment where I lack all perspective, I feel
like the worst person on the earth, and getting sympathy makes me feel even more selfish. I know that is completely untrue, and I see that myself at any other time, but when I am emotional enough...
So, I talked with Mya and we came up with one idea. We agreed that if/when I next feel like I need to cancel plans, I will text her and she will, at that time, only reply "ok.". Somehow, that feels selfish, because I definitely want her to be able to express it if she feels disappointed or anything else. But, the aim is to separate the "expressing need" and the "receiving reaction" parts from each other. That will (hopefully) make it somewhat easier for me to communicate when I am in that place of low energy; because it's really in everybody's interest that I recharge when I need to. And then I am totally open to talking about it later if either of us wants to.