I’ve been there with my sister. She’s now happily married, has a child, mortgage, degree, travels and I’m always compared. I’ve qualifications but can no longer work - I’m seen as “dosser” even when I did work and could travel and do things I loved I was still a dosser. Got my degree, dosser wasting time and money. I’ll never get married, achieve anything I wanted to because of my illness.
One thing that really helped me I got from a self help book, decades ago, and that was purchasing a notebook and writing every single thing I had achieved, and, it was every single thing. So for example I learnt to talk, walk and other things. Judging yourself by others, which is very very easy NEVER helps. There’s a poem called The (spelling isn’t right something like that) which explains it perfectly. Go google and read it.
It’s an exceptionally hard thing to do. But do, do try the notebook, and, some colouring pencils and really celebrate what YOU have achieved. What it took for you to meet those achievements. Start with being born.
Yes I know it sounds silly. A friend actually bought me the book and first lot of colouring pencils because I thought it silly but it really did help. Other things help me too but as they’re connected to my faith I won’t be putting them here as I don’t want to cause any offence.