The stuff you mentioned is nothing compared to:
Being enslaved by the World Nobles as a kid
Finding out your mom was killed
Seeing your dad shot in front of you
Your close friend that you grew up with was kidnapped, held hostage, raped, and then later on died
And finally having to sacrifice your mind and being forced to not see your adopted daughter anymore
Kuma's flashback is more emotional and more darker, and while the Loki flashback does have certain emotional moments, it is so far more focused on the lore and hype.