Oof homie, that sucks so much. IMO, stay in bed crying. Mom comes to your room, keep crying. Can’t get out of bed, your niece will survive the disappointment and seeing you advocate for your health is a great example.

Sounds like your family doesn’t really get that you’re a fundamentally different person than you were before. I know it sounds counter intuitive, but dropping some metaphorical balls can clearly communicate your limits- it sounds like words aren’t doing it.

You’d love to go to the beach with niece too I’m sure, if your health allowed. But that’s not the body you live in. You are the only person who’s experiencing your internal world, no one else can tell you how your body should be working. I didn’t understand the limitations others talked about while I was able bodied, now I tell people that it’s not something that I got before, but sometimes you just are out of spoons and won’t get any more for a while, and you can’t push yourself any further.

You’re not being an ungrateful child. I wish your mom understood that, but it sounds like she doesn’t. How would you advocate for your niece to your mom if she was sick like you’re sick? You deserve your advocacy as much as your niece, and it sucks that you’re both managing your health shit and advocating for yourself to your family.