Welcome, Illa.
First, I want to say that I've had bouts of depression myself. First time I can remember having that feeling I was like 9 years old. Maybe 8. So, you have my sympathies. I'm lucky in that I respond rapidly to the newer drugs like Paxil. However, that probably wouldn't have been a solution if I hadn't spent a lot of time with a very good psychiatrist.
So, are you on meds? Are you in therapy? How long have you been depressed? What about the past do you keep bringing up? Obviously, if it's still coming up, you have unresolved issues/feelings about it.
Fear can be a good motivator if you don't let the depression use it against you. One trick I have for beating the depression is to accomplish one little thing. I also anthropomorphize the depression so that I'm doing battle with an alien that lives in the back left side of my brain. Whatever works. Anyway, the depression tells me to stay in bed, that I don't feeling going to work. SO, even though I'm tempted to stay in bed, I visually draw my sword and get up. In the shower, I say "Ha, ha, Depression. You LOST, you sorry bit of emotional sludge."
The other thing I know is depression makes us incredibly self absorbed. It's part of its plan to isolate us from others and make us more lonely and eventually more depressed.
If your husband is the only one you've ever opened up to, maybe you could try opening up to more people? It will take some pressure off of him, and help you build bridges. If I start to feel depressed, and it's been three days, I dig out my address book, and I start dialing up friends. I take a deep gulp and I actually tell them I'm feeling depressed. This takes tremendous courage, but the outpouring of warmth helps me. And I've taken a babystep in the battle. I'm keepign my connections and I've put my allies on the alert that I might need them.
In a way, you've already done that. You came here. You shared. Share more.
Oh, and guess what... If you can force yourself to, Plan A will fix it so your husband won't want to leave. It's not you he's upset with, it's the depression. Plan A gives you a framework for behaving in a way that will please your husband. It's probably the same behaviors you did before you got depressed.