As soon as I started reading I was thinking "burn out". It can be different factors - life plays a role in rest and recovery as well as physically training/resting. Think about other things in your life - family, friends, school, other hobbies/activities, work, etc. Any stress there will affect everything else. For example the other day I worked for a few hours very conservatively in the yard in 98 deg F temps. I came inside, planning on doing a ride, and instead, after a brief period, passed out until the next morning. Apparently the heat really got to me because the stuff I did wasn't physically challenging at all.
Even a lack of stress can show itself - resolution with deep personal issues can make a fierce competitor into a meek one. A few of the very strong Juniors back in the day had massive personal problems - I remember one kid disappeared for a while, came back after dealing with a heroin problem, spanked us for a few months, then disappeared again. Etc etc etc.
The other thing I thought of was my first year as a "serious Senior". I decided that I was going to turn pro (ha!) and to do that I laid out a step-by-step plan, milestones I had to hit to realistically get to a pro level. The first milestone was to do well in the state RR, a 120+ mile affair. Since I'd never even ridden 100 miles I figured I needed to do more miles. That year I did 10k miles, give or take (my odometer's accuracy, a mechanical Huret, is questionable at best), I think I started 45 races, and I finished only one. The massive miles gave me a lot of endurance but as soon as one of the guys ratcheted up the pace I'd be off the back.
Over the years I've learned that 4000-4500 miles gives me the best return on the training dollar. Most years I'm lower, like 1500-2000 miles, and some years I've hit as high as 6500-7000 miles (all on more accurate cyclocomputers).
It sounds like you never really took time off, meaning a few weeks or a month, which is fine if you can't wait to get on the bike again but if you're soaked in negative thoughts then it may be time for a break. I spent almost 10 years without taking any time off except for illness (typically 1-2 weeks a year) and I was absolutely and totally enthusiastic about riding and racing the whole time. When I was finally burnt out I eased up and backed off.
It also sounds like you're doing a lot of steady work, great if you're going to do something like a randonneur event but not great for a shorter, more chaotic race. Training alone doesn't have to kill your jumpy speed but you need to incorporate some of that jumpiness into your training. When I say "jumpiness" I'm talking some efforts in the 35-40 mph range (solo, flat road, not unfriendly wind) and 40-65 mph (drafting trucks to screaming descents).
I didn't realize this until I had a power meter but drafting a truck, even going only 40 mph, causes your power to spike immensely as you alternately punch the pedals and coast. The same is true for very fast descents, where you're sprinting, tucking, sprinting, tucking. To give you some idea my max power is in the 1400-1500 range (ftp is about 220, w/kg is well under 3, I usually avg about 160-180w in a race, and I almost never break 500w for 60 seconds), I generally sprint at about 1200 in a race, and I see maybe 1-2 efforts over 1100-1200 watts in a race (including the sprint, so maybe 1 other effort other than the sprint). When descending on a training ride, or when drafting a truck, I will see multiple 1100-1200 watt spikes. Not sustained, but definitely spiking to those levels. If you're not seeing these spikes in training then you're not training for racing, you're training for training.
Hope this helps and let us know how you're doing.