How can a 30 yr start life from scratch ?

I have developed severe low self esteem because of no accomplishments and purpose in life. For context, I've been sitting at home for nearly 9 years ever since high school was finished. And now even my younger brother is gonna graduate high school. It is crazy how much time has gone by and I'm still where I'm as I was 21. Like I don't know what is it inside of me that is feeling shame and guilt. I still cannot get over the fact I have not graduated high school because it was my biggest dream to graduate and go college. That one goal or accomplishment that I never achieved is haunting me for years.

I got my GED and even enrolled in community college but for some reason even that felt like a failure since the majority of kids straight up went to university. I also realized I'm not a bright person. I don't have the talent, hope, passion, driven winning mindset, fast and smart.