Being a parent

Hello, im a dad to a 6yr old girl, love her to bits, and although I struggle with being a parent to a 6yr old for all the sensory stuff,  the one thing I really struggle with is being able to look at old photos/videos of her. I just end up in floods of tears, not just sad, but proper proper upset and crying, and I don't know why.

Part of me thinks its guilt for not being able to do the things I always thought I would do as a parent, the other part of me thinks it's cause its like a constant state of bereavement...kids change so much, and little things you take for granted like the way they talk and behave, change over time, and it's like the child you see in the photo/video isn't the same anymore :( 

Was just wondering if anybody else is the same? And if autism could be one of the reasons why looking at stuff like that is so hard, not liking the change.

Thanks.