I need relationship advice please!

Asked by Maebear (10) October 7th, 2020 from iPhone

Me and my boyfriend have been together for three years now and sadly I’m just not attracted to him anymore, we have fun together but I’m progressively thinking of him more as a best friend. I’m scared to leave as this has been my first serious relationship and he makes me feel safe but I feel like I need more than that from a relationship. Over the last few months I’ve began to have feelings for his best friend and I guess it could be out of pure subconscious boredom, but he’s a really lovely guy and I CANNOT get him out of my head no matter how hard I try. I know this is really harsh on my boyfriend, but I’ve been trying to pass it off as a silly thing that doesn’t mean anything and is normal, but I’m starting to like him more and more and I’m not sure what to do, I know really I need to leave my boyfriend because although I really do love him, I don’t think I love him in the right sort of way. But when/if I leave him, should I tell his friend how I feel? I don’t want to regret not trying but I also don’t want to hurt myself.
Someone help please!