This resonates for me and I shared a post a while back about that feeling of not being so needed and involved with the GCs and how hard it is to re-adjust.
With us it was not due to a child's illness - I am so sorry to hear of what you've been through and so pleased for you that he's doing well.
I do think there are parallels though - with us it was due to DD's illness and marriage problems.
I was feeling bereft at being excluded after I'd been so involved on a daily basis. The advice I received here was wonderful and really helped me, many of the people posting on this thread have echoed the same message, namely being happy the family have got through the tough times, feeling happy that you were able to help them through it, and taking a big step back and allowing them to re-build as a family.
But it IS hard and can be hurtful, even though I am sure your daughter does not mean to hurt you.
Sometimes I look back and try and remember how I felt about my parents when I was her age and with my own young kids and I am embarassed to recall how little I even considered my parents feelings at all....
Why Are Blokes Obsessed With Noisy Gadgets??
Angela Rayner lashes out and calls Sunak “pint sized loser”.