If you need financial help, ask under the "Finance, Tax, and Legal" forum.

Once you have the property converted to two legal units, it's going to depend on business vs. personal useage. 

My guess is You will need to go through a foreclosure process in this situation as a legal remedy.

Finally- you can eliminate 95% of the troubles and risk by simply having professional and legal screening and management processes, so don't sleep on that piece. 

If your credit is pulled for any reason, you will have to complete a letter of explanation and possibly provide more documents to show that no new debt was incurred.

Print them off, study them, highlight them, make notes, read some blog posts, and understand the subject.The second document he links includes precise definitions and a guide for landlords to use for screening support animals.

You still have the right to require documentation proving the animal is legit. https://www.hud.gov/sites/dfil... 

Here is a detailed look into this issue:https://www.biggerpockets.com/forums/51-tax-legal-issues-con...

The issue is legally be allowed to raise rents and getting around what the city believes is fair market rents.

And there is no problem that this document is saying that I have the permission but it is also signed by me?