When you completely nail a goal you've had all year, there is usually a mental slump after it until you decide on the next project.
I've had this too, often after a big race/races that you've been training for for months, the best thing to do it take a break... even if it does seem wrong at the time. But perhaps the lighter weeks on the legs leading up to this monster helped? Great run anyway!
Thanks very much. Still got a couple more races to get through before a proper rest. Easier weeks probably did help. Don't really need to do too much for now. Fitness is what it is and won't get any dramatic improvements in the next few weeks no matter what I do. Just need to keep things ticking over and not injure myself for now.