Been pushed away from him by parent

Me and this guy was dating in november. I know people say you can't believe in love at 19 but I loved this dude with all my heart...but my mom told him to never talk to me again. She called him a pathological liar. She claims I just didn't see it. We broke up in January but everything I do or say makes me think of him. Wishing he was hear. I use to look forward to go to bed to hear his voice telling me goodnight and every night he would tell me how much he loved me. How would I explain my feelings to my mom with out her saying mean things about him and making me cry? Help please :(