Depends, do you think that drug dependency is bad?
Personally I think drug dependency is indifferent. neither good nor bad - its the person dependent who is 'good' or 'bad'.
Tylenol PM may not be considered a "gateway" drug to other drugs, but I bet if I came over and lit up a joint and passed it to you 30 minutes before bed time you would leave off the T-PM and start smoking pot every night to help you go to sleep.
If that is bad in your books... you get the point.
Seriously go to the Doctor NOW. Tell him/her what you have been using, how much and tell them you can't sleep without it.
He/she will prescribe you with a sleeping aide for a short (very short) period of time to help you to ween off the drug you are dependent on now so you can sleep.
These people saying you can't get dependent on T-PM are, as you clearly know, Wrong.
You may not be dependent upon the drug itself, but you are dependent upon the effects of the drug. Psychological dependency is far more serious than physical dependency. It should not be downplayed nor dismissed.
Dependency and addiction are the same thing. One just sounds better than the other.