I know how you feel - my son's father is similar with me, and tells me he doesn't trust me with our child (my baby's daddy and I are not together anymore)... it really hurt me and I was depressed and blamed myself, too. But then I realized (through having a strong support system at work and in my moms' group) that I am a pretty okay mommy, and that my son's father was being a little ridiculous.
I realized I wasn't always the one to blame when he started blaming me even when he was the one who caused our son to fall down (by accident, on the playground). I didn't blame him for that, but he immediately blamed me for what he did, because I was the mom, and I wasn't watching our son more carefully... everything I did was considered reckless or not good enough, and so I started to criticize myself a lot. But you cannot be a good mom if you are always questioning yourself and telling yourself you are bad. Don't let anyone tell you you are a bad mom, if you are doing your best and caring for your son in a way that he can grow up strong.
That kind of relationship is not healthy for you or your child or your husband. I would recommend counseling, as other moms have said, and try to find a way to be independent. Find support in good friends, and see if any of your local friends can recommend a place to go to seek support and help. You need to be strong for your child, and please don't let anyone tell you what kind of a mom you are: you know in your heart how to help yourself. Please be strong.
p.s. - I did go for counseling, and it is helping me to have better communication with my son's father. It's not perfect, and we aren't together, but it's a lot better because I can stand up for myself, and also let go of what he says. When people criticize, sometimes it comes from their own hurt and shortcomings... best wishes.