Well, brava! you are already doing 24 mile rides! not shabby at all.
first of all; you can't expect to start and be able to ride with the DH and keep up with him. In fact, you might never.
Sit down and read 100+ posts on TE (here) most of us have to have our
OWN schedules and rides, not what hubby thinks we should be doing
You are already off to a great start. good luck and keep reading and keep biking!