So overwhelmed

I am 4 days postpartum and so overwhelmed and tired. I am just so worried about every little thing. I don’t know what’s safe and what isn’t. I keep wondering if I’m doing something that’s going to hurt her, or if I’m missing some cue that she’s in trouble. I’m afraid to sleep. And I’m so tired. My MIL is a huge help around the house and w the baby and my husband is just wonderful but I can’t help feeling like I just can’t do this. I’m not cut out for it. It’s too scary and too hard. Does anyone else feel this way?