Between YTA and NTA. From your post you basically state that your parents and siblings other than your sister treated you badly growing up. They bought things for siblings but not you and your sister tried to make it better by sharing with you. Parents neglected you and abused you emotionally at least if not physically and extended family got on the same bandwagon. Would I be wrong in guessing they also told you repeatedly that you’d never amount to anything?

YTA for rubbing your success in your family’s face but I get why you did it so NTA. You wanted to prove them wrong and you did it big time and now you’re afraid you’ve offended your sister and bil.

In a way your parents, siblings and extended family are partially responsible for you being successful if you think about it. You don’t owe them anything and you’ve proved your point. Apologize to your sister and move on. You’ve carried this anger around long enough it’s time to let it go.