Boyfriend hates my mom

Let me start by saying I love my mom. But over the years she has been manipulative and over protective to the point of harm; she read my journal, gets mad when I make plans without asking (I'm 18) and etc. Lots and lots. And to an extent her behaviour is due to her own life circumstances, but it's still been a bit extreme. Over the years my boyfriend has gotten to the point of hating her. He feels that she is too controlling and strict and that she should have more awareness of her actions, specifically the ones that have caused him grief. It's gotten to the point where he doesn't even want to see or be around her. I don't really feel like giving a ton of detail. What I will say is that I feel his concerns and feelings are justified if a bit extreme in his reaction, and that she has definitely caused both of us some grief. In the past few years I was too scared to say anything, since I was under 18 and living at home. Now I feel like it may be too late to really make a difference, and I love both parties even if I am being hurt by mom. He's said if I talked to her and she actively listened and tried to change he would MAYBE be more willing to be around her. I just don't know what to do; I've thought about having her come in with me when I see my therapist but at the same time I just feel completely hopeless about the situation and don't even know if the effort is worth it. Any advice?