Feel so alone

Whilst I have a caring husband and four grown up children who ask how I’m doing, I know they are all struggling a lot with my diagnosis a year ago, so I keep how I really feel relatively hidden and stick on the smile and get on with stuff (I obv have off days and am grumpy). Is that a mum thing to want to protect them (and my husband who clearly also struggles emotionally), but it’s wearing me down and frankly I'm sometimes thinking, you know, I’m the one who should be protected. I just can’t bring myself to tell them how I really feel...