Hair that had fallen out due to stress WILL GROW BACK, as long as your nails are growing and you're growing.
If you've got heat & chemicals on your hair, those are hair's worst enemies. CHANGE HOW you style your hair. GOOD hair care helps. Natural hair means no relaxer, no chemical to straighten your hair out, no styling heating tools. The way it grows out your root, that’s the way you rock it.
If you've straightened your hair in the past, STOP! It may grow slowly or none at all. Hair that you see now is dead. Wikipedia. But it has static electricity, when using heat, it sends currents to the roots, tampering them, they go into a coma. The RESULT of damage to the follicles from excessive styling or harsh chemical treatments. The result could take years! Think laser hair removal.
AVOID using oil on your hair. I don't care what they said, it makes your hair grow & thick, they're just trying to sell you products. I don't sell products since I don't sell products, I also don't get credits to advertise. They may even FALL out.
Example from YA!: “Coconut oil dried and made my hair fall out? But I want to use it again, a few months ago I bought coconuts and extracted the oil from them at home and used the oil on my hair, after washing my hair it felt dry (but generally oils make my hair drier) and it made my hair fall in long strands while washing it out (but I have to say that I was losing a lot of hair at the time before using the oil).”