40-45 hours of work a week should still give you plenty of time for practice.. doctors here in USA often work 80hours+ a week. That's a basic 8-9 hour day, 5 days a week -- which is normal for anyone. If you get 8hours of sleep a night, that still gives you 8hours for transportation, practice, dinner, hygiene, and whatever personal relationships you have. If you are only doing 2 hours in the morning, and 20min or so in the evening, that should be workable. Are you sure there isn't some other unessential time-waste you aren't telling us about? Like internet use, TV, (dharmawheel

etc.)?
Anyway even if there's other responsibilities you haven't mentioned, your daily essential damtsik is probably less than 2hours long. You mentioned that you "like" to do long practices. If your circumstances are such and you are depleting yourself and losing capacity at work, you need to fit your practice into an hour or so in the morning and get more sleep.
Then, you can do more elaborate extensive practices over the weekends. If your daily damtsik IS this time-consuming, then talk to your Vajra Master about your situation, and I am sure they will give you less of a commitment.
Personally, I find I can go with very little sleep for a few days, but then I need to catch up for at least a 8-10 hour stretch of uninterrupted sleep to compensate. You could try a schedule like that too, where you catch up on the weekends, as an alternative. You could also try taking B-vitamins during your workday, these help with alertness/energy.