I felt exactly the same. Had bad PND. Thought I had ruined my lovely life. Wished I could go back and make different decisions about having a family. Hated the baby days, wasn't thrilled with the toddler years but finally started getting pleasure from around 2-3yrs when IMO they become a lot more interesting and develop personalities.
I now have two of primary age and I would say that once they are at school you will suddenly see your friendship circle increase a lot (if you are open to it) and with people you will have plenty in common with - other women also craving to be women not just mums.
I would recommend you go to lots of activities/clubs with your LO and try to chat to people. I also met people through a PND listening group which was a godsend and I think helped more than the prozac I ended up taking. I realise you will be befriending other mums, but you will be surprised how many other mums yearn for a bit of child free fun every now and again and you might spark up some really lovely friendships.
It's hard to advise you on the work side as I have no idea what you do, but even if you can get a part time job in non skilled work, just to give you a break from being a mum and some interaction with adults on non baby talk terms that could make all the difference.
Also do you have any family who could so some baby sitting (day or night) and give you a couple of days off every now and again to go and spend time doing something for you?
Hold on in there though as like others have said it does get better and the speed at which it improves accelerates with each year. You just have to try and develop some coping strategies to get you through until it starts to change.
Big hugs though, I know how awful it feels. xxx