I don't have a HSC but I was one myself so I can empathise with what you are going through. For me it was the way stuff felt on my skin, particularly clothing. I hated socks esp the seams of them, and I can still remember how frustrated my mum got because she couldn't understand why I was so upset that my socks didn't feel right. I also hated jerseys and jackets because the sleeves of my shirt bunched up, and I hated wearing stockings coz of the way they felt. It still takes me ages to get dressed after swimming coz I don't like the feeling of being damp and I get upset if my clothes don't sit right or get bunched up. I can't wear certain types of material because the way it feels on my skin makes me cringe, and it took me a long time to feel ok about putting cream on my skin.
I was also very highly strung according to my mum, and took a lot of stuff to heart that probably wouldn't have bothered other kids. Esp when I felt that people might be looking at me/talking about me.
In my early teens I became very light sensitive and my parents got me blackout curtains because I couldn't sleep if there was any light in my room. I also had hypersensitive hearing and could hear the static in the radio alarm clock even if it was turned off.
I didn't like anyone touching me and brushing my hair was torture. My Mum told me after I had G that as a baby I wouldn't cuddle her or my Dad, and even as a very young baby I would push them away because I hated being touched.
My parents were very good, although I am sure I drove my Mum absolutely crazy and I still remember the meltdowns I had over clothes. One thing I do remember is how overwhelming everything was, even my feelings felt too big for me. My parents encouraged me to try new things and pushed me to do things that I found scary and overwhelming. I didn't appreciate that at the time - I hated them for making me do stuff that I found scary like meeting new people or going somewhere new - but I am glad they did that for me now.
I guess I don't really have any good advice but I wanted you to know that it sounds like you are doing really well coping with it. The things I remember from my childhood are Mum trying her best to understand and empathise with me, and although she couldn't make it better it made me feel like she really cared how I felt. Its not easy and I hope that things get better for you. In my case I still have some of my 'quirks' but mostly I grew out of them gradually as I approached my late teens.

to you.