Hi Jos
I think your post sums up how so many of us feel when we lose someone special in our lives. Though not a cancer sufferer myself, whilst on my husband's journey I also had a close friend whom herself was dealing with cancer (had been for over 23 years on and off). My friend was a remarkable lady whomI had known since we both were carrying our first children and who also, despite her own illness, found the compassion to show support to us. It is coming up to the anniversary of her passing (May) and is still sadly missed (the more so by her husband and three boys and grandchildren).
I hope that the time you had knowing Julie will remain a special memory in the days/weeks/years ahead. I understand your guilt and sadness but try, in time, to turn that into feeling lucky to have been there for each other and I am sure she would have enjoyed those chats just as much as you did.
The forum is a great place to offload and am sure others here will relate to your feelings and be along to add their thoughts.
Later today I am away for a few days break with my daughter and family as we try to come to terms with our own grief but will be happy to chat on my return (Friday) if you feel able to share your feelings virtually.
Sending you best wishes for your continued good health. Jules54