How do I (nicely) tell my family to leave me alone and/or stop being fake?

Your family sounds nice. Either you're taking what they say the wrong way, they thought you were independent when you were younger so they gave you space, or you're pushing them away. I know you can't pick your family, but deep down you love and appreciate them They're just not used to you living far away from them and being independent, and they probably miss you because they didn't see you for a long time. I think you're being unreasonable with your family. Maybe if you didn't have one, you'd appreciate them a lot more. No offense, but you sound self-centered, ungrateful and antisocial. Don't cut them off because you will regret it when they no longer walk this earth. You could always look into family counseling,have a talk with your parents about how you feel, or telling your family you'll call them, but not to call you. Or join the Witness Protection Program! Good luck!