Hi, having a young baby is exhausting and I can totally empathise about lack of sleep, previous stressful events and recovery from a c section. I found when I was 8 weeks post c section I was physically more able to do things ( without pain that is!!) so hopefully as each week goes by you will recover.
Lack if sleep is torture!! It does get better, honest - so hope you can hold onto that hope. And I do not think day's really understand what it is like, so try not to get so wound up if you can about your dh working, as they do not know what major surgery/childbirth/breastfeeding is like!
Recovery from pnd - medication helps, getting as much sleep as possible ( so yes, nanny, cleaner, family - if you got it, use it!!!)
Best advice is to speak to your HV - tell her about your symptoms, the help you think you need. They have post natal support groups for pnd they can put you in touch with. You can ask her to refer you to the peri natal mental health team who can assess you ( but it you already have a psychiatrist you would not receive treatment under 2 psych's). Also they can put you into group sessions to help you bond with your child as people with pnd do sometimes struggle with that. Children centres have support workers for mums with mental health issues or mums who are struggling with parenting, so you can request a support form if you think they could support you in parenting whilst suffering with pnd. So support there for people with pnd. Once a child is 18 months old there is much less support, as it is not in the post natal period and much less funding for adult mental health care so best to seek the support in these first few months.
If you want to go private then find a counsellor specialising in pnd is best.