stretch marks are the worst

Hayden
So when I was a freshmen in high school I was about 118 now that I'm a senior I'm about 140 and I'm starting to get stretch marks on my thighs I want to better myself and eat healthier but I must say it isn't easy. If I stated to do better in my eating habits and exercising more would be stretch marks go away? I honestly don't know. Please help. Thank you