I'm sorry, but I totally disagree with all the posters who have said that he's just a man and he's stressed out so you should take on even more responsibility. Bull. If he is having a problem, then you should certainly work with him to address it (therapist, meds, marital counseling, you name it) - that's what a partnership is. But the idea that you should just shoulder more and more responsibility because he can't get things together or is stressed out is just horribly unfair to you. You already have agreed to be both a full time wage earner and (in all likelihood) the primary caregiver, and that is a lot. A lot. Don't beat yourself up that on top of it you're not being a good enough/supportive enough, wife.
And, as far as making tons of sacrifices so that you can be a SAHM, if that's what you want to do, that's great. But if you like your job and feel like you can do a good job balancing the two, then you go ahead and do that. I agree that in this economy hanging your hat on one earner might be a mistake - I am also a teacher and my husband will be out of a job as of April. I never thought that I would be the primary earner, but for right now that's the case. Teachers have a good amount of job stability, and if the idea of having only one income is stressful, imagine the stress of having none!
So I'm sorry that I don't have more practical advice, but sometimes this site just really makes me mad. Just because you're a mom doesn't mean that you have to do everything perfectly, or even close to it. It is completely reasonable for you to want your marriage to be a partnership, and it's fine if you want your husband to step up and make that happen, stress or no stress. I wish you the best of luck getting him/the both of you to a counselor. And really, figuring out everything isn't your responsibility just because you're the woman. I think you're doing a great job.