It took my fiance a very long time to realise what you have about putting yourself first. I said there's a difference between being selfish and thinking of yourself. It was very hard for him to do it but he's so happy now he has. I told him to think of himself first, over me and everyone else, and make decisions based on what he wants. If someone disagrees they can argue it sure, but it's his life and he will never be happy if he isn't in charge of it.
It's a hard step for people to take but it's the best thing for you personally.
As for your husband, you probably need to talk to him. Tell him you want to share your feelings and for him to share his with you. Tell him how you feel when he says you're overthinking. He's probably overwhelmed by sharing, to be honest. With my fiance we have talked all this through and we've agreed if we're upset and something's raw we will tell the other we're going through something or dealing with something and not ready to talk about it, but at the same time answering basic questions so the other isn't sitting there freaking out. Also if we hurt the other person we have to talk up IMMEDIATELY so we know it hurt and can apologise and never do it again unless it's accidental or you're sensitive and took it wrong that time only sort of deal. Since doing this it's had a two fold effect - I'm not so nasty without realising and he's not so sensitive because he truly realised how much was upsetting him. It's been good, we've grown with it.
This might help you regain a level of intimacy with him and vulnerability that might open him back up. Tell him it's a social experiment or a game...
For the backstory:
http://www.nytimes.com/2015/01/11/fashion/modern-love-to-fall-in-love-with-anyone-do-this.html For just the questions:
http://www.nytimes.com/2015/01/11/fashion/no-37-big-wedding-or-small.html?_r=0