Yeah my 10 mile TT was about that but when i go out on my own i just doing 13.5mph average
I'm sorry but you will
really need to train harder. Looking at your Strava stats you're doing 30-ish miles a week at an average of 13.5mph. On a £2k Cervelo.
My 11 year-old, on a hilly 43 mile ride yesterday, did a 14.5mph average riding in front of/alongside me for about 2/3 of the ride (this is mine as his is 'private'
https://www.strava.com/activities/590546348 ) and a bit with my club. For info I slowed him down as I'm recovering from breaking 6 ribs a month ago.
Because his race results aren't as expected this year (no wins yet) AND we're doing a coast-to-coast ride this week
he decided to up his training to 100+ miles a week
at speed. That's a mixture of track, road and MTB training plus commuting.
After 6 weeks it's starting to pay dividends where he's now at the club's 'medium' chain gang pace rather than their 'beginner' chain gang.
If you're available this is in Stockton on 23-26 June:
http://events.stockton.gov.uk/stockton-events/stockton-cycling-festival-2/ to give you an idea of how fast circuit racing is. He's riding in the Under 12's race on the Friday night but the real speed will be in the U16's.
Sorry to be the bringer of bad news but you're about the pace of an average Under 12 racer at the moment.