Hello, I Am An 18yr Old Female. I Have Been

Hello, I am an 18yr old female. I have been an over thinker for quite a while and I stress quite a lot, thus putting too much pressure on my brain. There is now a noticeable vertical dent line on my forehead, which is visible in sunlight from side view. What could be the reason behind this? And what is the cure? Considering I can't get botox done at such a young age.