There is nothing wrong with the way you feel. We don't owe anyone a relationship, even a family member.
Some trust cannot be won back once broken. If you weren't supported or even believed during traumatic events, that's devastating. You going through something awful might have been hard for them to accept but as your parents that was their responsibility, not yours.
I can imagine having close family members disbelieve you made it extremely difficult for you to seek support.
I would suggest you do that now. Reach out and get some counseling. It is hard to forgive without an apology and especially without acknowledging they were wrong.
I would also say, you communicate often. You could cut that back slowly, at least enough to give you some peace from this. You just can't force love but you can take measures to protect yourself. I think in th circumstances you shouldn't feel guilty and your siblings putting pressure on you is not ok.
I've got another 'keen'... Ouch!