I want to marry my boyfriend, but I don't know how to go over it with my family

I've been with my boyfriend for 6 years. He came into my life at literally the perfect time. My mom passed away around the beginning of us dating, and even though he was working that day and his car broke down, he still came by to see me before I left for the funeral. Ever since then he's been such a positive influence for me. We lost weight together, he taught me to drive, helped me pursue one of my dream careers and helped me stay on track to graduating college. I feel like getting married would be a wonderful step for the both of us. I'm hoping within the next year or 2 at max.

My issue: I have extreme anxiety, and I'm never good as asking others for anything and my brother is very protective.

My only family left is my older brother and my sisters, so my brother is the main person I want to ask for my blessing and of course walk me down the aisle. He recently had a stroke, even had to go to the hospital this Thanksgiving once again. So I want to be sure he's well before I ask him, but I'm extremely shy and have a hard time asking for anything from others and I break down sometimes from the pressure of asking, mainly because so many people have done things for me my whole life especially my mom and brother for adopting me and my sisters into their lives. I never want to make them upset in any way.

How do I summon the courage to ask my brother?