Benadryl doesn't have abuse potential? Are you kidding me? It's the most widespread hallucinogen out on the market to date, right up there with Robitussin. Seriously. I don't recommend it, but I used to take about 500 mgs at once to get the effects. I would go to walmart and steal 300 pill packs. A good friend of mine accidentally overdosed on Benadryl and is dead.
Please, seek medical help if you think you might be addicted.