I can certainly relate to you. I am VERY hard on myself and I'm sure my dietitian friend thinks I'm my own worst enemy. Mind you, she can't say anything because she is just as bad. She lost quite a bit of weight as well, and has SO many similarities to me.
As far as resting from exercise goes, don't worry about that one. It is better for your health to have that break if you feel it is needed. I had to do this just the other week because my system let me know it had reached its limit. I couldn't function one day and worked out I had been overexercising. I rested for a few days and felt SO much better than before. I actually look forward to exercising now, whereas it had started to become a 'chore'. I lost weight the week I backed off from exercising, but some of it has come back on, which tells me it was probably just water loss or some such thing. But at least I didn't gain, which is what I was expecting. (just like you) I am now doing about half the exercise I had been doing, which seems to be just fine. I do 25 mins on the treadmill in the morning and 25 mins on the exercise bike in the afternoon, with alternating days doing 15 mins of strength training. I am hoping to up the strength training, but have only just started it and don't want to do the same thing I did with the other workouts.
Once again, please don't beat yourself up... and I'll try to follow my own advice at the same time... and just be really pleased with where you are at the moment and how far you've come. 67lbs is an AMAZING amount to lose, so you should just be patting yourself on the back, not kicking yourself in the pants. I have decided that I'm going to take some time just appreciating where I am now. I'm not panicking about food at the moment and am happy with my exercise, so I am kinda putting myself in 'maintenance' mode and I'm hoping to enjoy life for a while, without stressing. That is the plan anyway. Whether I manage it or not is another issue altogether.