Hello and thank you for your question. I’d be happy to assist you.
I understand your concern.
Well Tylenol PM also contains diphenhydramine which is same as Benadryl.
So you have taken three doses of diphenhydramine.
It can cause you drowsiness, flushing, low blood pressure, rapid heart rate, dry mouth, eyes, nose, rapid breathing.
So you should hydrate yourself with plenty of fluids.
Also monitor your blood pressure.
It's advised not to take other dose.
If you develop low blood pressure,pulse rate,confusion then see a doctor ASAP.
Let me know if you have any further query so we can discuss it thoroughly in every aspect.
Waiting for your response.
It’s my pleasure to continue this conversation until you satisfy.