Agree, what is the problem with taking ADs? If you had a headache, you would take a paracetamol. You are ill, you need treatment and medication (particaully as I get the image that whatever treatment you're currently receiving is not working for you). It's NOBODIES fault that you need to take medication, and in fact it can be a wonderful thing.
I took anti depressants and anti psychotics last year after the birth of my son. I had to, I was seriously ill. I believed that my baby belonged to someone else, that this was not my child. I hallucinated about his real mother coming to collect him, I was very nearly sectioned because of this.
Once they began working it was brilliant. I could think without these constant conflicting emotions crashing down on me. I could be rational. They did not turn me into a zombie, I still cried, but the crying had a definite reason, rather than 'I am so confused and everything is shit and I don't understand anything right now". Medication gave my brain the chance to slow down, the chance to process thoughts and the ability to deal with issues. I think you need them.
If you are worried about choosing the right nanny, ask your mum to help you. You trust her with your child, so she should be able to give good advice on who to choose.