So confused man

So ever since I was a young girl I always said I would never drink alcohol because I saw how it effected the people around me. Weed and stuff went with it as well. I’m a well put together student, I’m the top of my class and I’m on highest honors. I’m a senior this year and throughout my 4 years of hs I’ve never had a problem with saying no to that stuff, but recently I’ve been feeling really down, and I’ve felt a verge to try it, idk why but it’s just bothering me, sorry if this is childish.