Sorry about that Ally. Please don't feel that you need to do anything uncomfortable during a cruise. Even if someone in front hooks into a couple of corners, we always steady up on the straight bits so the group stays together. It's normal for the group to stretch out then bunch up again like a big rubber band as we each do our thing. The important thing is to go your own pace and never feel pressured to drive beyond your limits. We'd never expect you to do that, in fact we'd be disappointed if you did.
You did very well today and certainly weren't holding anyone up.