Babypoorlymama
You poor thing. Your anger and hurt is very clear to hear in your post. Don't apologise for ranting. Mn is big enought to cope with that.
I do know what you mean about wanting a good friend. It would make life soooo much easier for you to have someone to help you get through this.
Have you had counselling in the past, as well as the ads? While you are waiting for your intensive treatment, do you think that you can ask if your gp or health visitor can offer any support? Or Homestart, or the Samaritans, or even Cruse (bereavement counselling. The fact that your sister took her own life and that must have had a huge impact on you and your family and may well still be affecting you.)
How sad for you that your mum is not able to respond more sympathetically to you. And your dds in turn may well be picking up on how you are feeling and wanting to be reassured, cuddled, looked after. We've all had times when that is just too much for us, and screamed at them (well, I certainly have and it is a horrible feeling). Little ones are very very forgiving and if you can find time for them when things are not so pressurised to hug them and let them know how much that you love them, they will understand what your real feelings for them are. No-one can replace their mum for them. The fact that you are considering letting someone adopt them shows how really really desparate you are feeling at the moment.
Hang on in there, Honey, and keep on posting, even if it is just to let off steam.