feeling disrespected/interfering with your child's relationship

em
So, my boyfriend and I broke up on Thursday (26th Jan) after almost three years together, yet he realised we could fix things (reasons being my mental health and arguments), and we got back together yesterday (Jan 30th).
As soon as we got back together, he told his mum.
This evening he came over unannounced after a fight with her. He told her of his plans to go to a festival on Saturday night with his cousin, Connor, and her response was "oh you're going to go out clubbing and meet girls? That'll be good for you". He was offended, and corrected her saying "no, we are seeing a show, remember I am back with George now". She then started to bag me out, accusing me of being controlling and emotionally abusive (I have 3 types of anxiety, OCD & I'm depressed) and told him that he doesn't need me in his life and can do way better. He then yelled at her and came to my house.
I'm feeling extremely disrespected after that, especially as I go to great lengths to have good relations with his mother and I've always felt that she disapproves of me.
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My question is, would you ever interfere with your 18 year old son/daughter's relationship like that, especially after saying "you're 18 now, I trust you to make your own decisions?"
⭐️⭐️EDIT⭐️⭐️
I'm not abusive or controlling, she makes that shit up. My anxiety is under control 90% of the time, and when it's not, I NEVER make it his problem. I deal with it myself, yet sometimes I have my off days and everyone needs support at times.