I'm sorry you've been through so much OP.
Being worried about your partner's heart attack, losing part of household income, being worried about becoming homeless, looking on your own after your 5 year old daughter and your partner. It's a lot for one person to go through!
No wonder you can't carry on working now and you need time to recover after all of it. You have done a great job all this time to carry on, look after your family, secure any kind of council accommodation and apply for all the benefits. Most people have no idea how hard it is to do all of this on top of everything else while you have a rough time in your life.
I doubt there's plenty of families who won't end up homeless if one the partners will stop suddenly working for more than a few months.
I'm sorry to hear council will give you only one room in a shared house. But, you are right, at least you'll have a shared kitchen, which is better than no kitchen.
I wish you all the best OP, look after yourself, don’t give up, keep thinking positive, one day everything will be good again for your family. I know it's easier to say than do, but try not to be too harsh on yourself because it's definitely not your fault or your partner's fault. One day you'll solve your health issues, get back to work and life will be great again. 💐💐💐