How do you cope after losing a big amount of money in physical cash?

Pata hai aaj kya hua? Yesterday I came home via train from the city where my college is.

I had 7500 in cash 7000 tied together in a rubber band and 500 loose. I kept in the compartment of my laptop where laptop is kept.

I don't know hose fault it is.

My mom washed the bag, and dried it inside out from the window. Now when I ask her where she kept money, she said she only found 500rs. I can't find the rest anywhere in my house, I asked my neighbours, security guard noone could tell anything.

I feel so hopeless and worthless, wasting/losing parent's money. It hurts me very much. Neither my parents nor i make unnecessary expenditure. My PG rent is 6000 per month without food, I spend 150 to 160 on food and other things daily on average. I can't close my eyes without thinking about it.