I need boy advice...

I know it’s kinda dumb that I would come here for guy advice but I don’t have anyone else to go to for this so here goes... So I met this guy In October 2017, since then we have become really close....maybe too close, It started out as a friendly thing but now he’s starting to flirt with me, he’s saying I’m really pretty and calling me princess...and he tells me he loves me a lot. He is (and always has been) a really nice guy and I genuinely do love him and I think I might have feelings for him but it’s a problem....he’s 18 and I’m 13 🤷🏽‍♀️🤦🏽‍♀️..... so I needs some advice (please don’t be rude or judge me)