My mum doesn’t like my boyfriend

Me and my boyfriend are always out together and we’re always on FaceTime together,his mum knows about us and she loves but my mum doesn’t know about us until today.she took my phone and read the messages where he said he loved me and she raised her voice at me telling me it’s shameful and she was asking me who he was to me.She took my phone and rang him but thankfully he didn’t pick up,he rang me an hour later tho but she didn’t answer instead she just kept saying that she’s disappointed I said to her that I would never speak to him again and she goes I know your lying because you love him and I ignored her and later on in the day she brought it up again saying “why are you having a boyfriend at this age your too young” I was like I’m 15 I’m growing up it’s normal and I think she text him because I told him to ring me when he gets back from whereever he went and he was typing for ages but then he just blanked me I got a feeling my mum text him telling him not o speak to me then deleted the messages, I don’t know what to do I don’t want to break up with him but I don’t want to argue with her