It's all truly horrible. And it's abuse, and your children are suffering too.
Take your time to get organised, go to WA and talk with them, or to Refuge. Make plans, take steps. Take your documents like birth certs and school and medical records to your trusted friend's house, plus financial records and lease agreements, records wrt your car if you have one.
I think if your friend said you were welcome, she meant you were welcome warts and all, and I'd be willing to bet she knows your DS swears, and has taken that into account. My guess is she is very worried about you or she wouldn't have offered.
The first thing to attend to is the strengthening of you, because your children need you to be strong, so a few sessions of talking to someone from WA might really help here.
Ask for help with finding alternative housing or at least knowing what your options might be from your local CAB -- they will tell you how to go about finding somewhere else or maybe even getting the H out of where you are, which might suit you better. You will have to be prepared to make some compromises and do the best you can with what lands in your lap when this point comes. So you need to be mentally prepared to take the leap. Once you have taken even a few mental and physical steps towards freedom you will feel stronger.