Bad SAHM Depression

How do you guys get out of a slump? I’ve been in one for a year now and I have 3 kids ages 1,3,4 and I’m getting so depressed to the point where it feels like everything is a challenge to do. I feel like a failure and I feel so alone. I try talking to my husband but he doesn’t understand and just tells me to talk to someone. I’ve tried talking to a therapist but they never call me back to schedule an appointment and I’m desperate to get out of this mood I’ve been in. I can’t drive anywhere because my husband uses it to transport soldiers and equipment for work. So I’m at home all the time, I try going for walks but it ends up being a struggle with the kids. I feel like I just want to disappear, not die just not exist anymore. I feel like I compare myself to other moms who have it all together and they’re house is always clean. I do the cooking, cleaning, laundry, planning, everything. My job as a wife and mom doesn’t end until my head hits the pillow. My husband works until 7pm and by that time I’m getting kids off to bed. I don’t have anyone to talk too no friends or family. I just feel irritable, sad, frustrated, mentally tired, and angry. I feel like I’m on auto pilot and I’m separate from the world. I feel like I’m a rock, never moving just always in one place. I hate waking up in the mornings and I wish I didn’t. I just don’t know what to do anymore.