My heart goes out to you. Loss is so hard to deal with. I know just what you mean by things adding up.
I have been finding that allowing myself time to just be - to do the minimum I need to is helpful. The only things I'm making sure that I do is get to work, see my friends, family and SO often, get some exercise and make sure that my dog, love and companion, C is cared for.
I'm letting everything else drift for now.
Be gentle with yourself and concentrate on what's important to you. I hope you feel better soon.