Two become one- So where do we end?

Started off as the perfect high school sweethearts, but now neither of us are happy.

Since getting married a little over a year and a half ago, my husband has been getting more and more depressed and angry. I keep telling myself Well, as soon as this job works out, hell get better, As soon as we move into a new place, hell get better. But the longer I wait, the more unhappy both of us get. He is very closed off and private about his feelings, so every time I ask why hes depressed, he says he doesnt know or that hes wired to be this way. Im starting to think that its just me and that he would be happier with someone who shares more similar interests (we dont have many hobbies in common), but he always disagrees. Hes refusing to get help, and I dont know what else I can do for him, since he wont open up to me.

My happiness is starting to be affected by this negativity, since this is the prime of my life and career, and I feel I cant share my happiness with him since hes told me before that my success intimidates him.

Weve been together so long that neither of us know who we are without the other. What do you do when your soul mate isnt acting like your soul mate anymore? I dont want to give up on things just in case this is a phase hes going through, but I feel like Im the only one putting in an effort right now, since hes unemployed and also refuses to get a job, or help around the house, or do anything at all except wallow in his sadness.

I dont want to give up on things for lack of trying. Any advice for a young married couple going through this? How can I help him?