Thank you for asking your question on Justanswer.
An evaluation with a developmental psychologist would be a good starting point, if he has not had this type of examination before, it would help distinguish what part of his behavior might be neurological, and what part behavioral. Developmental psychologist are often affiliated with Universties. If you would like to tell me where you are located I can help you see what is available in your are.
It sounds like the dad may need some suggestions as well.
Of course a pediatrician or a child psychologist could be of help with prescribing medications to control some of his actions. If necessary this would be your short term solution.
Of course, as you well know, love,care and good intentions are always helpful, but sometimes will only go so far when an individual has severe damage.
This links to a page about attachment disorder which is another name for describing the results of early abuse. It does speak of the ways of mending a child with attachment disorder, which may provide you and the father some help.T(here are other pages on this web site that might be of interest as well):
This site regards XXXXX XXXXX are self abusive:
If you need help with referal or have additional questions on this subject, don't hesitate to write me back on a reply.
Thank you and good luck,