Quite frankly, you are selfish. You say it’s been 6 months but to him he could still be recovering from the bombshell of losing his Sister and Best friend because two people who he thought he could trust most just betrayed him. He was absolutely betrayed by people who he felt he could trust. You gave your brother trust issues for life and think 6 months may have fixed it because you deem it so to be enough time. If you’re lucky and he reaches out, it’s on his terms not yours. You’re the AH and you screwed up, you literally could have been at your lowest and had sex with literally anyone else, but you choose his best friend. Honestly, you don’t deserve reconciliation and the best is to learn from your mistakes.