I'm gonna have to be 'rude' here and drop some truths on ya. You want to know WHY people are telling you not to trick or treat? It's not just because people think it's childish (there are some things we, as adults, have to give up, and this is one of those things). People are saying it's only for kids because a lot of kids and some cities and neighborhoods are making ordinances where kids over the age of 12-14 (depending on the area) and adults aren't allowed to go trick or treating. This is because youth and young adults have in the past in those communities caused property damage, committed acts of vandalism, broken into people's homes, bullied and harmed younger trick or treaters, threatened adults, and committed acts of violence against adults, all in the Halloween spirit of mischief. Also, with the rise in awareness of *****, parents don't feel comfortable having strange adults around their children, even when they are with them. When they see teenagers and 20 somethings in their neighborhood trick or treating when the ban is known, they tend to call the cops. The cops showing up to hustle these people along and away tends to put other parents on alert, and often times they will end the night right then and there. Which means the kids suffer because OP won't find a way to celebrate the holiday without ignoring neighborhood rules, the fact that trick or treating is usually meant as an activity for the younger kids, that they could possible cause a scene that ends everyone's night early (which to a young kid, is basically ruining their halloween because they don't get to hang out and show off for as long and they get less of a candy haul).
OP says they have a problem being social, but they want to go do trick or treating, which in itself, is actually pretty social. People will ask about the costume, kids will want to know what you are, you often end up traveling in impromptu groups due to pacing between houses and people like to chat. So the issue I'm having is OP is set on doing this, ******** if they ruin anyone else's night and make a bunch of kids and parents uncomfortable. They are making ten tons of excuses not to follow anyone else's advice but the people agreeing with them who live in communities where it's okay to trick or treat as an adult (likely because they are known there, so they aren't seen as a threat). They don't want advice, they want a pat on the back, a 'go ahead and do it', even though their own mother is saying she doesn't approve and they won't be welcome at their house if they do it. OP does not care about the consequences of their actions, how it could ruin halloween for kids, how it's going to put a lot of adults on edge, how they could end up with a citation for doing it, how if they do, they lose their place to crash for the night. They don't care about the trouble they will likely cause, only about their own wants and needs.
OP, you have tons of ways to enjoy the holiday, and people have stated those ideas. You don't want to hear them, consider them, maybe even do some research yourself. This is a validation thread in the disguise of an advice thread. If you aren't going to listen to people, don't make threads here. Go to chatterbox if all you want is validation. It's a waste of everyone's time, and is really disrespectful to the people thinking you actually want help, when all you want is to hear you are right. That's the vibe you are giving off.
If you actually want to hear some advice, it's real simple. You are too scared to stay in your neighborhood so you want to use your mother's house as home base. While in her house, you abide by her rules. She's made it clear her rules are you don't do this or you get kicked out. If you want to be welcome, abide by her rules and find another way to celebrate. If you refuse, enjoy getting locked out and having to go back to the bad side of town. Realize that even if you do get to trick or treat, s**t tends to end pretty early these days. Tis not like ye old swaddling days. You'll probably be back home before 9pm (probably before 8, actually, but we'll give it an hour cuz your mom might live in a 'party' neighborhood). And going beyond that is REALLY ******** RUDE to the people in the houses. If you are dead set on trick or treating, you'd have to be escorting a kid. You said it yourself, they are impatient, and wouldn't understand your disabilities and would push you past your limit. They get disappointed, you get tuckered out and achy, no one has fun.
Ask your mother if you can gussy up her home base for halloween to impress the kiddies. You will be seen in your costumes, but you won't have to walk around and hurt yourself. While waiting between kids, enjoy a movie marathon. Get a skype party going with old friends who are staying home too. If that's still too boring for you, you obviously have a computer or access to one. Put it to use and look up haunted houses/hayrides/trails in the area. Print out a map, and go. They tend to be short, but fun, you don't really have to talk to people, you just have to scream purdy. You can go in costume on halloween. You can hang around outside the haunt after for a while and enjoy the actors outside scaring people. You can show off your costume while getting to actually do something AND not having to socialize overmuch if you don't want to. If you do not look for things to do and try, you of course will prove yourself right in finding nothing else to do that will work for you. Google is your friend. You can find a way to make this work where everyone is happy and you have a place to crash when you two call it a night if you bother to try.