Wow...
100-110 hours means that you work, say, 16 hours M-F and 12 hours on Sat and Sun (16*5+24=104), right?
16 hours a day means e.g. 8am-midnight plus commute plus shower. How do you manage to study for TWO HOURS after that? I guess, few people can give you advice - you probably know better yourself.
I can see several solutions:
1. If you want to do your work well, do not change anything. You will simply need more time to prepare for the GMAT. Perhaps you can postpone it for a few months.
2. Tell your colleagues/boss/subordinates that you need to reduce your workload so you can study for your B-school application. Explain that you will not be able to work effectively anyway since you will not be getting enough sleep, so you may make some wrong decisions, and the company may suffer. If this does not help, either switch to choice (1) or quit your job when you have enough money. You would have to do it anyway so you can attend a B-school.
3. If you don't really work 100-110 hours a week but are only present at work during this time, you may be able to study at work, particularly if you are sitting at a computer and if you have Internet access. However, there may be a risk to your reputation, which may also affect your B-school application.
4. If your position at your company is not very high and you cannot be honest with your manager, then simply go to bed late or get up earlier, sleep less, and keep studying. At some point you will get really sick. Then stay home and study in bed. Just make sure you have friends nearby in case you get REALLY sick.