I can't stay motivated.

First of all, what your husband can do and what you can do are two totally different things. Men have an easier time losing weight than women and that's just how it is. Don't compare yourself and suffer by it. It's also the eating less part of what he did that caused him to lose weight. Eating fewer carbs may have been easier for him to accomplish it but simply limiting carbs by itself won't cause weight loss unless it results in fewer calories being consumed.

As I'm sure you know, the thing about motivation is that it has to come from within. No one can give it to you and you can't give it to someone else, either. Every one of us has to find it for ourselves. You can, however, be inspired by others' motivation. Look at the success stories in these forums or strike up a conversation in the boards. Make a list of the reasons you want to lose/maintain your weight, post it where you can see it often and refer to it when you feel yourself slipping. Many here will tell you that rather than needing motivation, you need commitment, good habits and dedication. When motivation wears down, and it always does eventually, commitment, your habits and dedication will often take over and get you through the tough times.

And one more thing.... you'll see people here talking about the "light switch moment". It's that distinct moment in time where you are suddenly ready to do whatever it takes to lose weight/get healthy/strive for some goal. I know I can tell you the exact moment it happened to me and what I was doing when I felt it. If you haven't felt that click yet it's going to be very difficult for you. If you're not ready, you're not ready. It might be helpful for you to examine the reasons you keep giving up. Understanding and overcoming those reasons might very well be your key to sticking to it when you're ready.