Really surprised that I was able to do this. I think it was the first one that I was truly dreading as I imagined failure on the 5 minute run sessions, but I kept going. It does seem amazing after struggling to breath with heart racing after a 30 second run for the bus (that was what got me started). Also averting repeated depression. I've found it really helpful to read the ups and downs of others so thought I might try and contribute. Thank you to those who have shared - it's really helped me to keep realistic about progress.
Just to add, I'm using a rowing machine on my days off (21 mins), which I think has helped build up stamina, as well as trying to make sure I walk around 10,000 steps a day - usually around the park where I'm running. It's taken a while, but it's become a routine - I hope I can keep it up.