Sorry, everybody, I have been busy lately and I just remembered I had forgotten to reply to my own thread! Anyway, thanks for all your advice. I'm probably just going to give the suit away, since someone else could get better use out of it than I would, and Grandma never sees me swimming anyway. I wouldn't care so much if she just voiced her objections nicely, rather than immediately going on the offensive. Like in the other thread when I didn't come home for dinner, she could have just told me that there must have been some kind of misunderstanding, (though I'm sure there wasn't) but instead she chose to get angry. If she could just be nicer about it, then she wouldn't make me upset. I probably wouldn't listen to her, but I would at least get the impression that she was only trying to help, rather than trying to cause trouble.
Ko-Ko, I have issues with my own grandmother. Now, I had the aid of my father in figuring them out... and we realized she was treating me like my mother, rather than myself, who is very different from my mother. Maybe your grandmother is treating you like the personality of one of her own children rather than your personality- and might calm down if she figures that out.
My grandmother and I still have issues, but knowing WHY they happen makes it a lot easier for me to stay calm while dealing with them. That, and venting about them. I think it might be productive and helpful for you to find out WHY your grandmother does it. Whether there's a reason, or if she's just domineering, KNOWING will help you figure out the best way to handle it.