I'm so sorry to hear that you have had such an awful time I'm really pleased that you felt that you could reach out for extra support.
It's really important that you go and talk to your health care team if you don't feel that the treatments you are on are nor working as there are other options they can try.
Has your GP and health visitor put you in touch with other women who have gone through the same thing it really helps to connect with fellow survivors in these circumstances?
Have you been in touch with this organization they look like they have some really good support and information? https://www.ptsduk.org/what-is-ptsd/pos ... gLWG_D_BwE
I also know that Bliss offers help and this is the link to their website: https://www.bliss.org.uk/parents/suppor ... gIkaPD_BwE
With work, I know at the moment it feels really scary but it might really help you to get back to doing something from before the birth of your son. Have you spoken to your manager and colleagues about what has happened? They may be able to offer you extra support and a phased return to ease you back in gently.
I'm sure that in time you will be able to manage your symptoms and feel 'normal' again although I'm never sure exactly what that means!! You may even find that in time you are stronger following this experience than you were before.
Take good care of yourself, eat well and exercise it really does help, plan some nice things you can look forward to. Also, keep a journal of how you are feeling so you can look back and see the improvement over time.
Good luck, I really hope you feel better soon.