Lots of good advice here. Some of it conflicting, which I guess could be confusing and overwhelming. I think the important things are:

A. Never ever be afraid or embarrassed to post on here about how you are feeling - even if you feel it is a whinge or a rant (it's not, but I know that's how you feel sometimes).
B. Never be afraid of being judged negatively (on here or IRL). People who judge you can jam it.
C. Any parent who says they have never felt as you do now at one time or another, is either a liar or has a really crappy memory.
D. There is no shame in seeking professional help. Hundreds of women seek help from these services every day. They are experts and your feelings are more common than you think.
E. don't let the fact you were LTTTC stop you expressing your feelings or seeing help. It is percectly normal to feel overwhelmed and disillusioned when something you have wanted for so long arrives and the reality of the hard work of parenting sets in. In some ways I think that LTTTC makes it harder because you feel like you should be so grateful that you finally got a baby to take home. To find yourself struggling is not what you imagined all those years you were TTC.
F. When it comes to conflicting advice, it might help to choose the advice of some one whose parenting you admire and ask them questions directly.
G. As others have said, this will pass. I promise you. You just need to get through this phase of adjustment however you can. Seek help from PANDA, friends, family, Belly Belly... There are so many people who want to be there for you. Accept their help. One day you will pay it forward and help the next person.
H. Make sure you are getting lots of nutritious food. Take supplements if you need to. Drink lots of water. It will help fortify you. If you need help with meals, sing out. I bet you'll get more volunteers than you can handle

Above all, remember you are not alone. You are a good mum. You will get through this.

Xxx