Being honest without criticising

Hi all, Have been browsing the forum for a while and have gained a lot of insight from your posts - thanks. I have a question. How can I be honest with my partner about how miserable I feel about our relationship without criticising him? I try to voice issues as "complaints" rather than as "criticisms", as advised in Melissa's book, but he is super-defensive and often just takes them as criticisms anyway! Lately I've been feeling really anxious and depressed. I'm seeing a therapist on my own to try and get on top of those issues, and am experimenting with mindfulness, focusing on myself etc. However, I still feel pretty rotten much off the time and boyfy can tell. So what do I say when he asks what's wrong? If I'm honest and say that I'm depressed about the relationship he usually yells at me or tells me to shut up. So it's often easier to pretend that I'm stressed at work etc... however, clearly this does not get my needs met. Any thoughts?

We are going for couples counselling with an ADHD  coach soon so hopefully that will help but I'm curious what you all think.