Timecard honesty and procrastination

I am responsible for monitoring my own work time (work at home mostly). I ping-pong between procrastination and work-bingeing.  Some weeks I nearly kill myself pulling all-nighters to accomplish the impossible on a clients' unrealistic deadlines...or to pull out of procrastination and still make deadlines.  There's definitely been improvement since coming to PA, but this pattern persists.

I cannot seem to do much billable work if:
         1) there is no deadline pressure, 
         2) I recently work-binged,
         3) family problems are in play
         4) my pain levels are high (physical or emotional).

But when I have to turn in my timecard, my thinking goes like this:  How honest can I be and still bill 8 hours a day? Can I stretch :20 minutes of work into a billable hour?  Can I count that incoming client email as billable time even though I can't be sure if it took a minute or an hour to deal with it?  But if I'm rigorously honest I can only count 20 hours this week and then I can't pay bills!  But what about all those all-nighters I pulled, aren't they worth at least time and a half?  etc etc etc

My employer does not allow me to bill more than 8 hours a day, yet we never say no to a client even with an unrealistic deadline. It is expected in our small growing business that managers go to any length to meet and exceed expectations.  Nobody ever says I'm expected to pull all-nighters, but there seems no other way sometimes due to our no-brakes business, my own procrastination and/or poor time management skills.

Those weeks, my timecards show many fewer hours than I actually worked. Then I tend to feel I deserve some slack time afterward.  But when it's time to turn in my next timecard, I feel dishonest reporting 40 hours because I know I slacked.  Sometimes I spend HOURS poring through Outlook Journal trying to recapture every billable minute, to justify my timecard to myself and anyone else who might question it.

Other times, I just lie and assume I'll catch up another week when the deadlines are crazy - even while I know I already justified my slack week based on my last work binge.

I am 30 years in recovery from alcoholism and drug addiction, 12 years from eating disorders, and 5 years from codependency. ALL those recovery programs heavily stress the need for rigorous self-honesty.  Yet here I am, 3 years into PA, and only NOW realizing how fundamentally dishonest I am in my compulsive procrastination!

My basic dishonesty about time feeds the guilt/indecision/procrastination/shame cycle.  Yet, I can't see how to square this timecard issue under my present employment circumstances.  I welcome input from my PA pals. Thanks in advance.