Parents threatened me to dump my bf that I’m in love with

Okay so I told my parents things about my bf when he left me for another girl and they weren’t true at all which made the situation worse and they freaked out when I got back with him and said “if you don’t cut things off with him by tonight then I will get the police involved with him talking to your cousin. Literally just a casual talk smh. He’s 16 and my cousin is 12 and I’m 14. He didn’t even know how old she was Bc she looks and acts a lot older and when I told him he started kind of freaking out. I was mad and told my parents lies about him calling her cute and all that now I just messed everything up. I don’t know what to do. I just want to be happy. Any advice?