Thanks @Manderley I was thinking of you this weekend. What a journey it is Manderley
How do you think your Dad would like you to spend Father's Day and his birthday? Something special that would make him smile and bring you warm memories of the happy times you spent together? I'm planning to see what is showing in London, an Italian film, exhibition or opera (standing only!) as he was passionate about Italy (amongst other things!). I too have had a few moments of overwhelming grief and wow they took me completely by surprise and I came out the other end ok, it's normal - though until one experiences it we never know how it really feels and what the journey is.
Your Mum and Dad want you to live your life, take it forward and most importantly be happy so my advice is to do just that. It's great to hear you are moving forward in managing your Mum and her affairs, tough as it is to take on the responsibility that hopefully makes life easier for you short term.
We all lose our parents at some point; abandonment, adoption, fostering, accident, war, early unforeseen death..... I am a very fortunate person as is my family to date.
My father had dementia in his later years though we were able to have real conversations, share early memories and loving moments when his life window opened for me. They were very special, priceless moments where I learnt a lot about his childhood I never knew. Dad LOVED the memory book of his life we contributed to, it was his touch stone and helped him have the conversations he wanted to have with the 4 generations of his family and all his friends when they visited.
So while you are struggling with your Mum, a memory book worked for us to keep Dad's closing window OPEN.
Catch you soon.