Do you buy books or read them from the library? Are your parents supportive of reading habits?

At this point, especially 'cause you like reading anyways, I'd recommend reading books about SPD. Sensational Kids is the one that I have read and recommend. The Out-of-Sync Child is the other go-to book about SPD at this point, though I've not read that one. Because you have hypersensitivities primarily and are willing to read paper books, Too Loud Too Bright Too Fast Too Tight is one that focuses on hypersensitivities and does get more into adult SPD.

When it comes to reading - if you can afford it and it fits with what you read, I am extremely supportive of ebook readers, especially for people with sensitivity to paper. I sometimes can handle paper and sometimes can't at all. I read on my kindle always. The cheapest kindles are only $79, and while I don't know if that's something that your family would support, my kindle has been absolutely amazing for me, and I've likely saved the money my parents spent on it by this point. (My favorites are the kindles, but other eink ones are also worth looking into. Eink is amazing though, and ebooks don't feel like paper). And well, its easier to get parents to agree to that than therapy.

When it comes to the idea of whether you have Asperger's on top of SPD. Feel free to list as much about that as you want. We have parents of autistic children on here as well as autistic adults, as well as people who have only SPD and who's children have only SPD. I'm one of the autistic adults, and SPD and ASDs are a special interest.

As for reducing symptoms - yes, you can work on implementing a sensory diet without their help. What do you react well do? What makes you feel better sensory wise? Do different types of movement help? Does deep pressure help? Do your joints feel out of place and making them feel more in place help? Are you more stable after you've done hard work? Are there things that if you touch they make the icky feelings go away? What is positive rather than only what is negative? Figure those out?

Quite a few of us react very well to weighted blankets or other weighted products. Instead of going to a full weighted blanket (which is expensive or requires making yourself), trying to replicate that input with what's around the house is an option. I react very well to fur when it comes to touch. Eating applesauce or pudding through a straw is mentioned in Sensational Kids - that seems worth trying to me. My OT has found I'm more verbal if I don't sit in normal chairs and thinks I shouldn't have normal chairs - swings are best, then exercise balls, then rocking chairs. These are the types of things to look for.

Other people can probably help more with this part because I'm having quite a bit of difficulty converting thoughts to words, but hopefully that's something to start with. The books help a bunch too, and are worth reading.