The "PM" in Tylenol PM is diphenhydramine, also known as Benedryl. If the only problem you have is the sleep issue, without pain, you'd be better off taking Benedryl (or generic, shich is available OTC at any pharmacy). If you are on other antihistamines (like Claritin, Zyrtec, etc.) for allergies, check with the doctor or pharmacist first.

It can dry you out, so make sure you drink a lot of water.

I've found that it works OK for short-term sleep aid, you'd have to try for yourself and see if it works for you.

Good luck!