Are we doing something wrong?

This is an old photo but her facial expression is still the same most days.

This kid cries all. the .time and has since birth.

First, everyone told me it was gas, then colic now teething. Really? Is it possible that all of those things have caused her to be so miserable for the past five months straight, or is it just her personality? She is not happy laying down, being held, in her car seat, swing or exersauser. She is just never content. I have been trying to get her on a schedule where she eats every four hours but she wants no part of it. I just don't know what we're doing wrong.

We went out today for two hours. She didn't make a sound. The minute the car pulled in the driveway she lost her mind and continued to do so for the next 90 minutes. I don't get it. I'm sure now, it really is teething, so I've been giving her Tylenol here and there to see if that helps. (it doesn't but at least it makes me feel like I'm doing something.) We're trying teething rings, frozen washcloths etc., but nothing is helping and so far there are no teeth. I really don't get it and I'm starting get really frustrated.