Hi there, was your knee op related to your diabetes ?
I think what you're feeling is perfectly natural so don't get too alarmed, there are many type 1 diabetics who live to a ripe old age with no complications, it is achievable.
It does mean however, taking ownership for your type 1 and maintaining good control. Type 1 doesn't have to consume your life, you just need to learn to be mindful of it but not let it take over your life. I think by maintaining good control and not thinking about the future and what may or may not happen is the best way to cope, you can influence the future years of your life but certainly not worry about it, otherwise you will spend you life consumed by what could or could not happen and not enjoy life as it happens