How can you stop people worrying without pretending to be fine?

I feel absolutely awful when I see what I do to my mum when I am outwardly not okay. It means I try and hide how I feel as much as I can which makes things worse to be honest. But I’ve put my family through so much I have no idea how I can ease their worrying about me. I feel like I don’t deserve to be better because I have caused them all this pain :/