I want to end my perfect relationship with my boyfriend

We have been dating for 4 years. He is a gem of a human. Kind, companionate, caring, gets along with everybody. Family loves him. I love him very much and do not want to hurt him

Recently I have been feeling no intimate connection to him at all. I’m not attracted to him he is just my best friend. I don’t know if I deep down want passion and excitement and if that is wrong? I know lust fades and I’m not even interested in having sex or meeting other people…. I merely just rather be on my own. I’ve found a pretty motivating gym routine and he doesn’t workout and isn’t very health conscious. I love this new part of me and I want someone who motivates me… I have tried to get him to workout with me and choose healthier food but he doesn’t enjoy it and it’s like pulling teeth. I don’t know how to verbalize any of this to him without breaking his heart. I have been thinking about breaking up with him for the last few months but whenever I ask for advice from friends or family they say “why would you leave him he is perfect”. Or “nothing is wrong with your relationship it would be a mistake on your part”. What do I do!? Am I crazy