There is no shame in walking.
There have been two hill incidents I recall clearly. Once when I couldn't get properly geared in time, once when I just ran out of steam.
In both cases I couldn't get unclipped and did an Artie Johnson.
One of those AJ's was into brambles

This isn't a competition, it's a confidence building event.
Here's what I do.
Curse.
Go to granny.
Then if I find I can do better, upshift.
Simple!
You're a strong rider, you can do this.
2008 Trek FX 7.2/Terry Cite X
2009 Jamis Aurora/Brooks B-68
2010 Trek FX 7.6 WSD/stock bontrager