Unfortunately you are unlikely to get custody of your child unless the mother is assessed as completely unfit to care for it. Probably you consider she is unfit, but your opinion is not the same as a board of social workers/doctors or whatever. Just because she trashed your house doesn't mean she will be an unfit mother. If she doesn't want you to have anything to with the baby, she presumably wants nothing to do with you herself, or is she expecting you to support her financially? You should get some proper advice from Citizens Advice Bureau (if you are in the UK). There may be similar organisations in other countries.