I love wearing leggings but paired up with huge baggy sweaters, but i feel like this isin't sexy enough. Do i have to wear skin tight outfits to have sex appeal?

Nope!

If wearing traditionally “sexy” clothes makes you feel sexy, that’s fine and you can do that. But if you feel most sexy when you’re comfortable, and being comfortable equates to wearing sweaters and leggings, do that! Confidence is always, always, always the sexiest thing, and it’s hard to be totally confident when you’re uncomfortable.