I know how you feel OP, and I think years of struggles have taught you to tell yourself off for self-pity, or at least it had me. But sometimes I also find it helpful, and realistically yes, it is deserving of pity.
It's the same with physical health (my daughter has a hidden physical disability), the pain and the struggles are tough, whether they are physical or mental, and sometimes feel unbearable.
My issues are closest to @Hearthnhome, and I also sometimes find it really helpful to think 'The people you see as going about their business and happy, may well have Mental Health issues but trauma has taught them that to survive you must hide it.'
But yes, I do sometimes feel jealous of others and quite possibly wouldn't pick my own problems out of the friends' 'problem pool', as some suggested most of us would. Having suicidal ideation and C-PTSD (on top of recently diagnosed ADHD) for 35 years out of 50 is not fun.
Having neurodivergent and/or physically disabled children is also not fun, and doesn't help things - I get particularly jealous of people whose children don't struggle. But it's not their fault, and really it is my cross to bear the best I can.
On the positive note, I think the struggles, whether physical or mental, make people more mature, resilient and compassionate, or at least I'm telling myself that 