Well it does sound as though the police are pursuing this with the intention of laying criminal charges if evidence exists. If they were not going to pursue charges, then they would not spend their time drafting and obtaining the Production Orders. Further, within the Orders themselves, the police have to set out that the information which they seek to obtain will provide evidence of a criminal offence.
I would agree that the most likely charge they would be looking at is criminal harassment, from a domestic perspective. If you have no prior criminal record and this is a first offence, the Crown may agree to deal with the charge in a manner that did not see you receive a conviction or criminal record. There would have to be some mitigating facts however, such as your mental health. Getting into counselling to address your concerns on an ongoing basis would be a positive step to show that you have recognized that you have areas regarding your mental health that you acknowledge and want to work on to ensure that things like this won't happen again.
Ultimately, if you are charged, it is highly recommended that you retain the services of a local criminal lawyer as this is the best way to ensure that you come out of this in the best way possible. It may be costly, however a criminal record would have a much greater impact than a minor financial expense. As for your H1 Visa application, this could be significantly affected by a criminal charge being laid against you. In fact, it would cause your application to be put on hold, but not necessarily denied. They would likely just wait to see what the outcome of the charge is.
Please let me know if you require anything further as I am happy to chat further.
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