My Mom Is Causing Issues In My Relationship

My boyfriend and I are relatively young. We have been dating since November of last year, and we have had little to no problems. My Mother sounded very supportive of the whole ordeal until more recently. She has been self projecting her insecurities of hers and and my Father's relationship onto me and my relationship. From things such as accusing my boyfriend of cheating on me, or vice versa, to even accusing us of having sex. (We are most definitely not doing so. This is an issue because we are younger than 18.) Another thing she does is accuses him of being a pedophile. I'm rather small and short for my age, meanwhile he is rather tall and has a lot of facial hair for his age. So she claims he only dates me because I'm childish looking. Which is obviously not the case. I feel so bad because sometimes I get upset with her, and I take my anger out on my poor boyfriend. Sometimes she says these things to me, and it gets to me. A few days ago I sobbed in his arms and begged him to tell me if he only wanted me for sex, all because she had screamed at me a few nights prior. After these accusations, he will no longer touch me around her or my father. He wont hold my hand, put his arm around me, or even so much as let me lean on him once my Mother becomes present. It makes me feel so blatantly disrespected in my own relationship that my Mother has to make it this upsetting. Just yesterday he walked me home from his house. My Mother was standing on the porch, and he wouldn't so much as say "I love you" back to me. It really hurt me, and whenever I came inside she taunted me for it for 20 minutes, telling me how he didn't want to say it because he doesn't mean it. My boyfriend has also become more agitated with the whole situation and will angry tell me about it. I understand the situation involved him, but he complains about it despite not having to live with my Mother. The big kicker for this whole event happened about last month. I was getting out of the shower whenever my boyfriend called for our nightly call. I wasnt dressed yet, but wrapped up in my bath robe, sitting on the sink while he was talking to me about his day. Immediately, my Mom comes in and starts screaming at me for having him on the phone while I'm not completely dressed. I can slightly understand where she's coming from, but at the same time... 1.) He had no clue I was getting out of the shower, nor did he have any idea I wasnt wearing clothes. 2.) We were NOT on a video call, so he couldnt see me. 3.) Even if he knew, he wouldnt have cared. He isnt the type to be overly sexual over dumb things like that. I'm sorry this was such a long thread, this is the first one I've ever made. But honestly, I just need some advice. Advice on how to stop letting this get to me would be nice. Or at the very least, some positive words of affirmation? Thank you all very much. <3