Is my boyfriends parents right or wrong?

So here's something that's really bothering me at the minute, basically I have some real crappy "friends" or should I say HAD. 

A few months ago me and my boyfriend got into an argument, it was alcohol fuelled and I thought at the time that he had pulled my hair, we later discussed it and it was an accident/misunderstanding. He had tried to pick me up from the top of the stairs when I'd fallen down and stood on my hair as he pulled me up. Me being drunk and a survivor of a previous domestic abuse relationship, I quite clearly reacted to it badly as I was under the influence. I sent a message at the time (4am) to my friends saying he had pulled my hair. A few months has passed and I've fallen out with them over something unrelated to my boyfriend. Out of pure spite and immaturity they have sent a screenshot of the message to his family. It was just a normal morning, we woke up, spent the day together and at 8pm yesterday he got a phone call from his mum saying he needed to go round and talk to them. He came back very upset and said he needed to split up with me, apparently he feels torn between them and me because they are very unhappy that this could have affected his job if it had got out, understandably. However, if it had been posted publicly I would have jumped right in to tell them it is untrue. In the ofigibal conversation I had retracted it and said it was an accident a few hours later when I had sobered up. Me and my boyfriend discussed and dealt with it at the time.we had moved on from it. I'm feeling very hurt that they have made him feel like he cannot be with me. Me and his family have never had any previous issues and I think it's unfair that they have judged me from one malicious screenshot without hearing the full story. It's unfair in my opinion for them to make him feel like he has to choose between his relationship and his family. For the record, our relationship is absolutely perfect and we have no reason to break up at all. He stayed at his mum and dad's last night under their order, mostly to keep them happy, and has returned home today. But he has turned his phone off so I can't see whatever messages they will be sending him right now about him coming here as they believe he shouldn't be with me. He's 26 years old and should be allowed to make his own choices and mistakes. I understand that parents worry, and they want to protect him. But he certainly doesn't need protecting from me. We have been together just short of a year and he has been living with me for the past 6 months and in that time his mother has done everything in her power to try and make him come back to live there, I think she has empty nest syndrome as he's never had a partner before me and I think it's because I'm the first woman to come in and take her child away. She needs to let him grow up and be an independent adult but she won't. Am I in the wrong for saying something drunk, that I retracted, apologised, he knew about it at the time and I've apologised for the screenshot being sent to his family? They have been so quick to judge me over this and I think they are wrong for making him feel like he has to stay away from me and making it difficult for us to be together over some petty manipulative screenshot from quite clearly an immature girl who's problem lies with me and not their son? Granted, they shouldn't have been brought in to it and I've told my "friends" the severity of what they have done and I do not want anything further to do with them or this childish disagreement that has been blown way out of proportion. What am I supposed to do? My relationship is at risk when it absolutely shouldn't be, I'm being judged, pushed out of his family and I can see just how much this has upset him as he loves me just as much as his parents and doesn't want to go against them or me. Has anyone encountered something similar? I doubt it but I really need help with this one. I feel uncomfortable him being here now knowing his parents are angry at him for coming to see me. He's literally here watching tv and offering to take me out for breakfast, just like a normal day. But it doesn't feel normal because I don't want to be sneaking around and avoiding them seeing us out and about. 

Your comments are much appreciated,

Anna