I have a 10 month old rottweiler mix that I adopted from the shelter when he was 15 weeks old. He's a great dog, great with my two kids and me, but since my husband just came back from a deployment, he doesn't do to well with him. He's not aggressive, just terrified of him. I think most of it is because my dog is a little shy and doesn't like to play really rough, and my husband is always trying to get him to rough house, which I really don't approve of, 1 because I don't want the dog to think it's okay and try that with my kids, and 2 I can tell it makes him uncomfortable, but my stupid husband thinks I just want to make him a "sissy dog"... but that's a whole different issue.

Another thing, is when I'm at home he's a completely different dog than when he is outside. He sticks to my leg like velcro, jumping at anything that blows in the wind and if anyone comes near us he just stops, tail glued to his leg and shakes. He didn't used to be this way, it's all been going down hill the last few months and I just don't know what could have happened to cause him to act this way.

It makes me really nervous because I don't want him to end up biting out of fear (he's snapped at my husband before). I'm afraid to be the only one to work with him and have him still be scared of my husband.
Any comments/advice would be great.

Your husband is setting this dog up for disaster. Rotties are one of the top breeds when it comes to aggression. I think any breed can be raised to be a good dog, but rough housing will only lead to trouble.

Does your husband care if this dog attacks one of the kids? If not, then he can keep rough housing, when the dog gets bigger he'll learn the hard way.

Talk to your husband, the dog is trying to tell him something, and he's not listening.

Can you check around and find a training class near you that uses positive reinforcement? It would be great to find one that both of you could attend. Your husband may listen to a "dog expert" saying the same thing you are trying to tell him. A class that uses Gentle Leader Headcollars would be ideal--they often help shy dogs gain confidence and trust in their owners.
This dog was not around men for many months, and probably was never really socialized to men. The sudden rough play is overwhelming.
You are not trying to make this dog a "sissy", you are trying to make him a calm and well-behaved pet.
There is nothing more dangerous than a dog that bites out of fear, and I agree that pushing this dog past his comfort zone is a direct path to disaster.