Husband suffering from depression (help?!)

Betty
Hey guys. So my husband has been suffering with depression for a while now, on and off. He has his good and bad days but they are mostly only bad. I am 35 weeks pregnant and honestly I am suffering with him. He never wants to do anything, go anywhere. He is always either at work or sleeping. He does not believe in taking antidepressants or seeing psychiatric doctors. I am trying my best to help and support him. I listen to him, let him vent. I baby him and am very cautious about what I do or say around him. I try to give him hope and support his goals that he often forgets he ever had. I don't know what else to do. I don't want to be selfish but honestly I need support too. I'm about to become a mom and I have so much going on. I want someone to lean on and someone to tell me I'm gonna be ok. I wanna know I have that back bone but I can't tell him all this because I know it will get him down even more knowing he's not being and can't be supportive. 
I know my hubby's depression has to do with his dead end job that he is pretty much stuck in. (He can't change careers its too risky as we need the money) He has gained a ton of weight from comfort eating and the weight gain makes him even more depressed and then he eats more. It's a cycle.
His baby sister had cancer and that effected him tremendously. Thankfully, she is in remission now. And previous to becoming pregnant I was sick with fibromyalgia which caused me to leave work on disability. I feel better since falling pregnant though I Am still not working.
Basically, his world fell apart around him and he never took care of himself, only others and now he is falling apart. 
I would love some advice on what I can do to help him if you or anyone you know had been through this please let me know. Thanks in advance.