If you are going to mix sedatives in with your stimulants, then you might as well not take anything. I don't know what stimulants you have or how you react to them (especially when sleep deprived) so I don't know how I can give you advice on what's best for you at this point. You know your body and how you respond to drugs better than any of us.
If you have a long enough acting stimulant, I would stick with that. If you have short acting stimulants, you will either crash half way through work or have to keep crashing and redosing. I usually have some coffee and maybe some ephedrine in the AM to get myself going a bit but not heroic doses or continued throughout the day because you'll probably get nicely irritable and feel even worse later if you keep dosing those. If you have a longer acting amphetamine, you may have better results. Modafinil would be ideal but I doubt you have access to that in a pinch.
Make sure to eat well, if you load up on sugar, much like the caffeine, you will feel better briefly than counterproductively crash. Avoid simple carbs and sugars and try to get good balanced carbs and lots of protein for more sustained energy. Loading up on B vitamins and such would be useful as well.
