I have not read the replies.
To me you sound like a normal mum who has just had a baby. I think it is easy to get in this way, if you factor in hormones, being tired, a baby needing you, running a house & looking after DP it can be very easy to lose yourself.
I think if you do little things for yourself you will start feeling good. Start with shaving your legs, putting cream on, doing your nails. These little things can make a huge difference to how you feel. If you can get a hair cut that little bit of pampering can work wonders.
If you can give yourself some money, say $100 get some cheap boots, new pants & a top, they can be your going out clothes. If you don't have the money to spend, can you sew or get second hand, you don't need to spend a fortune.
I don't have any experience with depression but I do know how sometimes things can get on top of you & how overwhelming being a mum is. I take a bath, paint my nails, make a cuppa & read a mag/book, just a few minutes to recharge the batteries. I think once you start thinking of everything you feel is wrong it can seem too hard to sort out so pick 1 thing you want to change & do it.
If after you change these things you feel no better then I think you should see a Doctor.
& don't be so hard on yourself