First of all, thank you to everyone for your supportive messages.
I've been back to Acute Emergency Care this morning. The good news is a blood clot in the lungs has been ruled out. I'm still breathless, but it's easier than last week, the doctor has told me there is still a rattle in my chest and she believed it's a combination of chest infection and asthma. I will have to have another CT scan in a couple of months.
I have been referred back to GP for blood tests to check for heart problems, but otherwise it was a relief to be sent home again.