Zoony,
If you feel bad don't hesitate to call an ambulance. We had them out about six times before last Christmas, they were so patient and kind to my husband. I did say I was embarrassed we'd called them out so much, but they told me if we were at all worried we were doing the right thing calling them. My husband was taken in to hospital and sent home again a few times until on Christmas morning they took him in and took his condition seriously, got him on the right medication and sorted him out.
I'm telling you all this because you do need to be a bit pushy, shouldn't have to be if you are feeling ill and weak. The AF can make you feel very tired too.
You sound like you need a home care package, they should have arranged this for you before discharge. Try your GP surgery or Social Services. If you have been poorly for a while and needed help(even if you haven't had it) you may be entitled to Attendance Allowance, contact Age Concern and they can help you with the forms. This gives you money to pay for the help you need.
Hope you get the help you need. And don't be worried about calling for an ambulance if you feel you need it.
Take care, Jac