Welcome Hermione2 these forums are for just that support and there are many nice people who have alot of good advice.
I myself do not know what Adult Attachment Disorder is or what it does, as I am not a professional though have had relationship troubles and do have problems.
I am sorry for your break up with your boyfriend and and that you must be hurting. It sounds as if this issue with your ex and his family is pretty much something that has been going on for along time. Though as difficult as it may seem, there may not be any way to convince the entire family to get professional help, however if you are to come in contact or see you ex again I would encourage that he get counseling.
Though his mother is calling the shots, he is still an adult and free to leave at any time only doesn't seem like that is in his mind frame. I would say that the best thing if you were to get back together is for him to get help to get the courage to feel independant and feel he CAN leave home and that it is an option for him.
If he is not willing to get help or feels there is not a problem, then I would say as hard as it may be, to look for someone who is more 'grown up' and independant. In a way if he doesn't change, and you do get back together it seems as to look like an uphill struggle complicated relationship with uncertain future for you.
I wish you the best and don't forget to take care of the most important person involved in this YOU! Love yourself and be good to yourself.
God Bless
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~KRIS~
If you think you have totally gave up, you haven't, because you are here!