When and Why MELTDOWNS

Yesterday had gone good...then going to bed last night out out of the blue there
it was.............A/ MY Meltdown.....
I can't not figure out how or when or why they happen out of the blue.....
I was totally talking about something different....talking to Abby and my Hubby....
Then
POW!!!!! Tears are rolling down my cheeks...uncontrollable.....missing my Ken so much....just want to see him so bad....................
I just wonder where the Meltdowns come from......Out of the blue...It hits so strong as if it was yesterday......
Ken, sure missing you baby....Love mom