Rebdoniel is wrong, by the way. Someone who is Over a D’rabannan is still a M’challel Shabbos. It’s an explicit Peirush HaRosh in Horiyos, if I recall correctly.
Assaf: I am very sorry for your situation. I would always advise being honest with family. And if you can’t bring yourself to tell them, maybe you should start thinking that the life you’re living isn’t worth it. If you can’t share it with those who love you, then you have to think there’s something wrong with what you’re doing. That aside, it is always very important to make sure not to burn bridges in case you ever want to come back.