Also, warn him in advance. "DH, I want to talk to you about a couple of small household issues tonight after the kids are in bed, is that okay?" Don't spring it on him as soon as he walks in the door, or just before you guys go to bed.
You have to deliver a "shit sandwhich". Basically, sandwhich your negative comments to him between two positive pieces of reinforcement. e.g. "DH, I love you and I value you as my husband, but I want to talk to you about something. I know that you respect me enough to listen to what I have to say. I need you to listen to this without interrupting me, is that okay? Well what I want to talk to you about is....." Then, at the end of your complaint say "thanks for listening to this, I know you'll take it on board". Sounds cheesey but it may work.
extremepie I would second writing out a letter to him, not with the intention of delivering that letter, but with the intention of getting your thoughts straight and prioritised and removing the emotion from the discussion. Avoiding confrontation and communication is extremely unhealthy in a relationship IMO.
Simply put, tell it like it is without getting emotional. Tell him it's not what you want. Remind him of all the things you like and love about him, but be honest in telling him what you want.
Things between us have been fine, mostly because I'm surpressing my true feelings - if I'm honest I'm really unhappy how things are at the moment and feel I need to have a very serious discussion with him about what things I would like to change if we are going to have a future together.
The problem is, he takes any sort of negative comment really really badly. This is mainly why I have been surpressing my feelings for so long because I just can't bear the big screaming argument that will result, we just end up in a situation where he doesn't listen and won't take any of my comments on board because he is so angry and defensive.
I can't live my life without challenging him on his behaviour because I'm worried about how he will take it and I don't want to give up either.
What is the best way to do this? I've been thinking about writing a letter but that seems so....I don't know, it just doesn't seem right. I've thought about having another person there who knows us both but can be a bit more objective but I think that would probably make him angrier that I told him our relationship needed work in front of other people.