He has reluctantly agreed because he knows I want this. I'm having a complicated pregnancy and I am facing an early induction in a few weeks time. I'm absolutely terrified of medicalised birth - I had dearly wanted a homebirth - but I've had to shift my thinking and accept that I will be in hospital, under consultant care, with loads of VEs, drips, monitors etc. Ugh.
So I'm trying to make the best of it - give myself the best chance of having as positive a birth experience as I can. This is my second baby. I had a mixed experience in my first birth - natural and positive first stage followed by medicalised very unpleasant second stage - and DH doesn't seem to understand how traumatic that was (still is) for me. He also refuses to read anything about hypnobirthing or relaxation techniques - seems to think it's all mumbo jumbo and "we'll deal with it all as the situation arises" 
So should I go ahead and book my Doula, knowing that he doesn't really want it? He has agreed to it but looks very unhappy. He is worried that she will be an "interfering busybody" who is going to take his place and/or tell him what to do.