Well, after nearly two weeks off due to bronchitis (never good when you are asthmatic), I decided that my breathing and lungs were normal (losing my voice and sometimes have a rattly cough but this is not from my lungs anymore) so I thought I've give week 6 run 1 another go.
Came home from work and got straight out there, with the thought at the back of my mind that if I began to struggle I would just stop and walk home. But after the first 5 minute run I still felt ok, and after the 8 minutes and at the end! My legs took a little while to get back into it, but once they had remembered what to do it was fine.
When I checked on Strava afterwards my pace and distance was roughly the same as it was when I did it the first time nearly 2 weeks ago
Thanks to everyone for the advice to just carry on from the week I was on - you were right! It felt so good to be out there again - I'm hooked, aren't I!!