Yes, high doses of benzos can give you a nasty hangover. Of course, it's not a nauseous room-spinning type hangover like with booze; the extreme fatigue, depression, irritability, etc are very common and can be a miserable experience. Also, even though you stated that you "remember 80% of the night," amnesia and blackouts will probably become a common occurence as your tolerance increases and you begin taking larger doses.
Remember that even though it's relatively difficult to overdose on benzos, these side effects can be dangerous. In addition, mixing them with alcohol, opiates, or anything else that slows bodily functioning can greatly increase the dangers.
Lastly, benzos can cause physical dependence over time, like heroin. The withdrawal symptoms are hideous and can be life-threatening. So if I were you, I'd stop taking them so frequently and recklessly. In my opinion, benzos aren't even recreational--they are just useful tools for anxiety, insomnia and for taking the edge off stimulants.