He didnt. But that's only possible through physical contact, even Klaus and Elijah have had to touch someone to gain another persons info. Lizzie naturally felt those thing. Gaslighting...you can't be serious. Your really blowing this out of proportion my friend. Josie said that because they are twins whi are used to spending alot of time together to the point of codependency(of course she's goig to notice the void of her sister not around her).
That was more of him wanting to help keep her life(granted going the wrong way about it). Sebastian said those things in a self-destructive state, he wanted Alaric to kill him because he didn't want to go on living in the cruel modern world without being able to attend the school. Your really giving this guy waaay too much credit for being a little charming. Sebastian literally asked Lizzie if she had some human blood when he was stuck in the ground and after getting free not once tried to get blood from her.