banana I'm so sorry you're feeling everything getting ontop of you. I'm surprised how badly your friend's treating you, if anything she should be supporting you more as this may be a lovely way of her spending time with children and having a positive affect on them before her and her DH work out how to move on from their situation.
What a rubbish start sassy, especially as you have exams to deal with along with 3 children, bfing, moving house, DH away at work, housework. May I say your ex sounds a bit of a bastard!!
jodeylea it's nice to see you on here again, I was wondering how you were getting on as it's been a while. I'm sorry to hear you're struggling too.
maple I thought you meant yourself about the big poo too! Sometimes you just have to go! 
clumsy I don't think you'd be selfish to go back to work. If you'd be happy to go back and you can find childcare for your LO's why not?
I also think having a sibling is a fantastic thing. I can understand it's hard for you and your first but it will work out. I think it's lovely for children to grow up together and learn to share and support another person. I know I never had that feeling that your DD has as I'm a twin but I can't imagine having grown up without her.
It's good to know that everyone has down days. I'm lucky that I have my sister to talk to about things, and she has me. It annoys me that people expect you to say everything's fine. Whenever I've said anything even slightly negative about the situation to my PIL's they just tell me how I can't complain as their kids were so much harder, and they had 3. They want me to go back to work and harass me about it all the time. I'm not ready and anyway I earned less working 3 days for them than I get on maternity allowance so I'd be crazy to go back.
I think I've just won the monster post competition! 