I would just tell them that you have personal issues right now and won't be going into field service in the foreseeable future, but you will be sure and let them know if you do have any hours to report, there is no need for them to contact you. You don't need to tell them that that day will never come.
This organization is all about reporting and structure and dotting their i's and crossing their t's, meanwhile, people with real problems are being ignored and wrongs are not addressed if it's not convenient to them.
Congratulations on your work on healing from your abuse and getting out of this heartless organization, your life will only get better.