You have a few big issues here that you should discuss with a competent business attorney. Unfortunately, the answers will all require a detailed review of your current business documents. You need to make sure that you are not personally using a corporate opportunity in starting the new business, and confirm that your current shareholder agreement or other governing documents does not give your current co-owner a right to participate in similar business opportunities.
As far as the loan goes, you may be able to pledge your equity in the first business to fund the second, unless it is restricted in your bylaws or shareholder agreement.
The simple answer is to find a local business attorney and meet with them to discuss your issues.
Good luck!
Answered on Jun 29th, 2015 at 12:16 PM