Cass, Hugs to you.

My situation is different from yours. I have two foster boys. It is a long story but they are my sister's boys and somedays, I have to work really hard to love them like my own.
You are not a bad person for feeling this way. When you have a baby, you have instant unconditional love. Love of another person's child is different and can be complicated and somedays you really do have to work at it. I have my days too, where I am angry that things are the way they are.

Hang in there, you are doing a fantastic job!