How much is too much exercise?

Two separate issues:

1. No weight loss for a week and a half is completely normal when losing weight. For men, no scale loss after 3-4 weeks indicates a need to drop calories. Before that point, short periods of no weight loss (even gains) should be expected from time to time.

2. Here's an article on overtraining: http://www.aworkoutroutine.com/rest-recovery-overtraining/

Having lost 140lbs myself (regained a few due to illness but heading back there again now) I'd say a year is definitely too tight a timescale. You'll feel healthier doing it more slowly and the time passing helps you to adjust to new portion sizes and a new way of eating/exercising. Doesn't sound like you needed to ramp up your exercise sessions. I'd recommend setting them at the rate you see yourself able to do forever and getting used to what is now your new life (rather than just a year of your life) as to maintain your loss you are going to need to be a different person to the one you were when you were gaining.

How is your sleep? I am really into cycling and I find when I ride too many miles too many days in a row, I can't get to sleep like I normally do. Maybe that is just me, but it is a measure I use to know I am overdoing it.

More is better is always a tempting proposition, but generally not advised. If you look at most things in life, moderation tends to be the path to follow. I personally have a history of going overboard and in the long run it hasn't served me very well...nagging overuse injuries the last couple of years...burn out...muscular imbalances and impingement, and increased stress on the body that jacks around with hormones, etc.

I'm working with my trainer this year to take a more balanced and moderate approach to my fitness...in the past I've trained as if I'm just going to go out any day and race or participate in some event pretty much year around...in the earlier days of my fitness, I felt good and it wasn't a big deal...my fitness was up so I just kept doing more and more and more. This year I'm basically taking the approach of 3x weekly in the weight room with only walking if I'm antsy on those days and 3-4 days of cycling on non lifting days...one sprint interval, one tempo ride, and one long ride...an optional 4th recovery ride, but I've been using that day to do other interesting things like going to the rock climbing gym or swimming, etc.

I have two primary events scheduled for this year and I will train specifically for those but otherwise I'm looking at 6 days per week of exercise...some weight lifting and moderate cardio on the bike...nothing crazy. I'm already feeling a lot better.

Keep in mind that rest and recovery is very important to improved fitness...regular exercise is good for you, but it can also be a substantial stress on the body and your body needs rest and recovery.

ETA: substantially underfeeding and incessant exercise is really going to jack around with your hormones and impede fat loss. I'd take a more moderate approach to things personally...even though that seem counter intuitive.

Your net calories are seriously under what they should be. My guess is that they aren't accurate or you'd be headed for malnutrition/injury/worse. Your exercise calories may be severely over-inflated which means your net calories are much higher than you think. Anyway, not enough information to be certain, but your net calories, for a man, should be more than the 600-800 you've shown on the chart above. I realize that's after exercise (net) but it means, that if your calculations are accurate, that you're exercising too much, or not eating enough. Since you say you aren't losing weight as expected I'd suspect that the exercise calories are over inflated. Just a thought.

You need "recovery days" otherwise your muscles are always "torn". Over time, you can possibly do some serious injury to yourself. Try to mix in some gentle stretching / yoga if you really feel that you need to exercise every day. Also, try incrementally cutting down by 500 calories by taking 166 calories off meal 1 for week 1; both meal 1 and 2 for week 2; all three meals week 3. You should see some progress. Finally, I can't see your meals, but, try going paleo (low sugar/carb / high protein/unsaturated fat) and see if that helps.