I taught adults TEFL at one point, and however good their vocabulary was, the tone and the way you said something can totally alter the meaning of a sentence or phrase , which was some of the most difficult things to understand, Also when learning to use the telephone, the lack of body language and gestures made quite a difference. So I used to give them the same phrase on a table , but each person was asked to say it in a specific way, annoyed or enquiring or whatever, and the others asked to recognise it. As we do such a lot in a shorthand way with emails etc., I was wondering if something has been misheard or misread, and led on to further problems.?
Disabled myself , but still used to both running my own life, and giving my opinions on a variety of other things, I know the frustration when your body cant do what you want it to, but whatever other people see, inside you are still that person with your own choices to make in life.
I used to offer to take two or three people who could no longer drive to the coast. But I would think in advance what I was prepared to do, and then offer the trip on my terms. So I would offer the trip, where I would pick people up from their homes, and drop them off at a convenient place at the coast, with a planned return time, but with the proviso that if the weather turned very bad, we could ring each other up and rearrange the timing. But when people started saying things like "Oh we could go to the shops together " I immediately said firmly but politely, "No, I am not offering to do that. I will only be going to the drop off point and returning later to pick up. That way we are all free to do as we want." Ruffled a few feathers the first time, but as I said later, I am happy to offer to do a similar trip and share the fuel, or we could go to somewhere like RHS Harlow Carr, on the same understanding. Since then have done several trips and although it sounds bossy the first time, everyone actually likes the freedom to do their own thing, and those that like the same thing can go together.
However, when it comes to how you run your life, you have survived and made choices without a major catastrophe, as your being alive to tell the tale shows. Disabilities may cause us frustration and annoyances , but do not cancel our ability to use our brain as we have done so for many a year. So I tend to speak firmly, not with a raised voice, but just stating, "Thank you for the offer, but I have my own preferred way of doing X" or stating No , I'm only available to do A, not B and stick to it. Even if it looks somewhat ridiculous , so many years ago, I was offered a lift to somewhere, which I accepted , but said that I must be back by 3pm as I needed to be back for my son coming home. It was the first (and last!) time I went with that person, who blithely continued to wander about and say there was plenty of time etc. I simply decided that I wasnt going to get uptight about it, and found out where the nearest taxi rank was, then went up to her, and said I am getting a taxi back as I did say I needed to be back by 3pm, and didnt wait for her promises to just be a few more minutes but left. I got a reputation for meaning what I say and that also goes the other way too, as if I promise to do something or collect someone, they know I can be relied upon.
If I am offered some unnecessary assistance in a supermarket, I usually smile at the person and just say, "No, I am fine, thanks for asking" and carry on. My somewhat sarcastic answer to someone in a dress shop, who kept trying to get me to look at something I did not want, after twice politely stating that was not what I wanted, was to look straight at her and ask " can I just check. I am the customer and I am spending my money" . Even if you dont want or need to say that to someone, I find that going out with the assumption that I am entitled to receive the same treatment as others, and that I should also be polite to others, is a good standpoint and it works well for me. Locally now , people are used to seeing me around and know how I tend to be, and on bad days I will ask if I need help and thank them for it.
So be kind to yourself, I think you should award yourself some small treat to cheer yourself up, whether that is a good cup of coffee or a g and t, Then if you still feel annoyed about it ,get either a cushion or a pillow and use as a punch bag, or in a positive way, make some bread. Home made bread is delicious and thumping the dough gets rid of frustration and you can eat the result!
With regards to your sister I think you have two options. Either you try some of the above to feel better yourself, and then dont speak about the hassle. Alternatively you might possibly write her a letter, rather than an email , explaining your views and attitude, or perhaps arrange to meet her in a neutral place such as a pleasant cafe, where you can see how it goes from there. The only important thing overall is that as Churchill said "just keep b-----ing on, but in your own sweet way. If you can pull it off , you could always irritate the person concerned by saying in a pleasant voice with a smile on your face "oh yes I know that is the way you do it, but I prefer my own way" If you practise that phrase it can be so useful, as they cannot say you are being rude, yet you remain implacable to changing your plans. They may think you are a awkward so and so, but do you care? Best of luck, whatever you decide to do, and know that GN's are full of lots of ideas and experiences and you will find plenty of other people choose your way. Hope you will let us know which if any of the things you tried. At 81, when things rattle me I sometimes think the most annoying thing that I can do back to whoever or whatever is to keep breathing!