That's where we're at with my brother, Maryz
Counselling is a great suggestion, and I did have it after losing my dad, but where my brothers concerned it's always hard as so many people, unless they've actually lived with autism, just don't understand.
I've learned to detach, and becoming a mini autism expert has helped now that I know why he needs to have ten conversations recounting the exact same thing, and why his clothes are so massive! It's also helped in putting a lot of things from my own childhood into a context that now make sense to me.
But my own life is ridiculously full and I found having to go to weekly counselling was a bit stressful, as well as the cost of course.
Anger is something my brother defaults to and really it isn't anger but frustration, upset and anxiety but it all translates itself through anger and if you didn't know him, you'd probably find him really scary as he starts shouting and ranting and pacing manically, sometimes talking to himself ... (My mother used to do the same.) the difficulty is since he can't very well wear a T shirt with 'i am actually heartbroken with no self esteem and heartwrenchingly lonely but can't express it' people recoil from him, understandably. (He also gets very 'shouty' when nervous.)
I never used to feel resentful but increasingly I feel it.
One of the really (and probably the most significant) insights made in counselling was that my identify had been carved by being his polar opposite as a child: where he was sullen and withdrawn I was happy and outgoing, where he was moody and morose, I was polite and keen.
As teenagers it was a bit different as he fell in with drug taking festival going cool kids and this was largely his Time. He harks back endlessly to it but couldn't move on. His friends from that era have been balding businessmen wearing suits with wives and kids for over a decade now and he just hadn't noticed 