You have been racing now for the last 4 months, once sometime twice a week and residual fatigue is starting to build and motivation to train hard is faltering. So time to shake things up a bit.
There is still 8 to 10 weeks of the season left and it’s what you do today that will give you your fitness in 3 or 4 weeks’ time. So use your time wisely. Ditch those junk miles and be specific. For most of you working full time with busy family lives you only have 6-8 training hours to play with each week. So look at your remaining events (distance, topography etc) and ensure your time is spent building your current strengths and fitness to complement this type of event. Be Specific !