Help!!! 2 Rumors are going around and I want them to stop!!?

Okay so there's this girl named Alayna. She well she's a ******. She has given me trouble for the 2 years and now this one. I have a boyfriend and he's rich. This is probally gonna sound bad but I had no clue till I started dating him and went to his house. Well Alayna started a rumor that I'm only dating him for his money. And it's really annoying me. And it's stressing me out Wich always makes me pms. Then she started the rumor that he's cheating on me for my best friend. And she's never nice to me. She gets me in trouble at school and ruins my life every time she gets in the middle of it. I want the Rumors to stop and her to get out my life. Any advice?