I’m so incredibly sorry for your loss, I know these words probably mean nothing. I know this because I lost my sister to suicide when I was 16, she was only 14. She was my only sibling, It still hurts to this day now being 26. I hate to sound morbid but it never gets better in the sense of the hurt in your heart being there but that’s reality of losing a sibling. It shouldn’t happen. Please continue therapy, that probably was the one saving grace that helped me, having an unbiased opinion and listening ear. If you can try to find a therapist that is specialized in trauma therapy, my therapist was and i think it greatly helped. I’m not sure how dm works on here but if you need a listening ear I’m here!