Is anyone else extremely sad?

I will be 11 weeks tomorrow with my second baby, my son is two. Lately I have been so sad I don't even want to get out of bed. I don't remember if I was like this with my son but is anyone else feeling the same way? I just want to be by myself. I don't even like when my fiancé touches me, I hate to be touched lately and I just feel angry and sad. Any advice on what to do to make me feel better?? :(