Correct bands

[Deleted User]

Ive been running for years but up until now purely just for fun . I have entered the gsr to raise money for a wheel chair bound boy at our school . We entered all together basing our times on a average between us all . I've done lots of training all on hills and have got 12 miles down to around 9 min miles but would ideally like to get in in under 1.5 hours ( as my sponsorship will double!) what are the chances of battling through the green wave , I'm completely terrified that I just won't be able to make my way through as I'm not a pushy person ( externally) but inside in desperate to get a decent time ?!! Help !!!!