Can God "undo" some of my regrets?

I think of deaths in my life today, 3 of my loved ones:

1. My grandmother, when I was 9 years old. Air ticket to Sarawak from KL is still very expensive, we took midnight flight after close shop to rush back but she's already gone in her sleep peacefully. I wish I'd die like her without pain, just old age and just retire into sleep and gone.
2. My friend, Cheong Chung Hoe, 1984-2016. He passed away because of dengue fever at the age of 32. He is one cheerful guy, funny, and sometimes heart warming with his friendly and lovely acts. 
3. My uncle, mom's youngest brother. He died alone in his apartment when everyone was at some events or away from home. Sudden heart failure if not mistaken. Life's so short, at 51 he left his wife and 4 kids and his parents too.

Life's sometimes just too short to feel regret. Can God "undo" them? 

Well, live everyday like it's the last day of your life. Love as much as you can.

I wish~