I actually have a perspective about this!

I am in your husband's shoes. My fiance has had a few MDEs, although he is managing his depression/anxiety well now, due to the right meds and a good therapist. Your husband is frustrated with you, and I can completely relate to his frustration! He guaranteed does not understand mental health disorders, as evidenced by his command to "snap out of it". An excellent book that you should buy for your husband is How You Can Survive When They're Depressed by Anne Sheffield. I belong to a related online forum, similar to this one, but that is intended for the spouses/significant others of people who suffer from depression/bipolar. It has its share of drama, but your husband will find an entire community of people who can relate to his frustration, and while there are some who wallow in the frustration and don't move on, there are also many others (like myself) who urge understanding of those who suffer from mental health issues and diligently work to find solutions to the problems. If your husband is interested in checking it out, PM me and I'll email him the link to the forum.

I urge you to not spend too much time wondering if he's right that it's your fault. That's the last thing you need, is more guilt on top of everything. It doesn't matter whose fault it is... if you're a team, then you're a team. Each team member needs to try their best and pull his/her own weight, and that does not necessarily mean that the weight will always be equal. Just do your best.