Is it good if I dont use anything in my hair?

Im black and have African American hair is it good if I dont put anything in my hair. I wash my hair once a week then I let it air dry then I put it in a ponytail do you think thats why the back of my hair falls out? Sometimes i'll put oil sheen on my hair so it doesn't look so dry. My hair is thick and long (2-3 inches past my shoulders) but it seems like no matter what I do the back just breaks off and it ends up shorter than the front of my hair. I use a deep conditioner when I wash it and use detangler and an a treatment for my ends so they wont get split real bad but the back still falls out. Could it be the ponytails I where all the time? My mom and my aunts say it is but I dont think so because most of my friends hair is almost to their butt and some of us have the same texture hair and all they do is wear their hair in ponytails. By the way I have relaxed hair and if everything I try doesn't work then Im cutting off my hair and going natural, so it can grow healthy.

PLEASE HELP ME!

You need to use some type of moisturizer daily such as profectiv daily leave-in strengthener or elasta qp manago butter. You need to use some type of oil at least 1 to 2 times a week- profectiv makes a good 3 n1 oil for breakage and olive oil, coconut oil and jojoba oil are all great as well. I hope this helps you on your path to achieve greater length. the ends treatmens are great, glad that you are doing them. Try wearing loose buns, bantu knots, braids or other protective styles from time to time instead of a ponytail all of the time. That ponytail is just asking for trouble and if i may suggest a book-The 2003 edition- The black woman's guide to beautiful, healthier hair in 6 weeks by carolyn gray.

give your hair an alternative, try something different than just a ponytail..put elasta qp mango butter on your ends and that should stop the breakage