(You will have to spell out the details very specifically, as disclosure is key, especially with such a large profit.  

If they are, the threat of that disclosure could be leverage.

Did you sign any documents like a non disclosure or representation agreement with this guy?

Full disclosure I am a certified Xero advisor so I am biased.

Pretty sure there is a disclosure out there that says you as the borrower have reported all outstanding loans.  

What about state required disclosures?

I'm not real estate savvy but I know full disclosure between agents/brokers and clients are necessary. 

The best advice I can recommend is to find yourself a good fee based financial planner (full disclosure:  I am a CERTIFIED FINANCIAL PLANNER(TM) who will take the time to get to know you and your situation, your goals, and who will help you craft a plan that encompasses all of the different areas of financial planning.Good luck on your journey and I hope this helps.Ed 

Hi all, Disclosure: I work for Lima One Capital.

You are viewed as having greater expertise than the public as a licensee and this disclosure gives legal notice of presumed skills and abilities in dealing, where a fair price in a contract may be reached with the parties having similar knowledge of the subject matter.