So have just completed the 20 min run for r3w5 and I feel pretty awesome. I went slow sometimes really slow but I didn't stop and didn't walk. I expected to be more breathless but I think because you consciously keep a pace you are comfortable I wasn't.
I also used a tracking app just to see how far I went and I did 1.3 miles so I know that this isn't great for 20 mins but now I know I can do this I can start getting faster.
I wanted to say thank you to everyone on here who has been so positive your support really helped me.
oh and I had a little hangover this morning as it was my birthday yesterday and I still got up and did it and now I feel fine