How many benadryl pills does it take to overdose on?

This is not an official or anything, but I have been taking dyphenhydramine for sleep (which is the active ingredient in Benedryl), and I have been taking these for so long my body does not react to the "Normal" dosage, and I will take anywhere from 15-25 at a time. It will dry your sinuses out and it can make you hallucinate. If you do not eat it will also cause vomiting.