No teaching yourself will only help you with form. You get resistance training with a partner and corrections you cannot catch with a teacher. Muay Thai is nice but a mixis better. Look up savate Thai cross training... CSW those guys have more head movement. Anyone and I mean anyone can compete in Muay Thai, it's like training pants to real fighters.

You can not teach yourself Martial arts because you are not a teacher because you are learning martial arts because you don't know martial arts, therefore you can not teach yourself martial arts.

Yes, you need a teacher. Self-taught folks always end up being terrible. You need someone there who can correct your mistakes (and you WILL make them, even pros do), and you need other bodies, preferably SKILLED bodies, to work with in training. Even a not-so-great teacher is better than no teacher.

Why do you even want to "teach" yourself. You obviously can't. Because if you do, you'll start to get bad habits and screw up. And YES get a real coach.

so I'm teaching myself Muay Thai. I don't go to a martial arts school and I was wondering if teaching myself would be as effective if I was taking martial arts class I train a hour a day for a month now.