I haven't been in your position personally, but I have had an ob kind of like that. When I second guessed him, (got my gp to second guess him too) he gave up on me altogether. Did what he had to do & nothing more.
If I was you I would go public, but thats totally up to you. I have faith in the public system & midwives as I've been there 3 times & my only issue with was the first time with an ob. Well 2 seperate obs, but anyway.
Don't let him take control. Its up to you if you stay with him or not, but don't let him bully you. Have him know that you are well informed of your rights & that you know your chances of a perfectly healthy baby with a natural labour aren't as far fetched as he's trying to make you think.
A doula could be great support & reassuring, but as far as I know, a doula can't tell an ob what to do & is to avoid any confontation if possible. They are there to support you & can't cause conflict. Your DH on the other hand, can stand up for you.