It’s not much consolation, I know - but millions of people and families and kids have been where you are right now. It feels overwhelming, un-conquerable and final.
It’s not. You’re absolutely going to be alright, it just takes time.
It’s important to be around people at this time. Seek out the support of friends, family and work colleagues. Hell, ask your boss over for dinner.
And exercise. Get exercising. It will help your head more than anything else.