Document everything negative in your own system that  happens  or does not happen that gets in the way of your doing your job well. Keep track of how profitable your work has been to your employer and how much they are losing when the frustrate your efforts. Save all emails. In my law firm we have a joke that the 'e' in 'email' stands for 'evidence'. Properly handled , judges and juries get to see this. I would begin leveraging my contacts and identifying targets for future employment with a 1-3 year horizon for moving on.  Do this on  a  system that is under your sole control. Do not take anything that is unauthorized like company secrets or customer lists. Above all else, speak with an employment lawyer in your own state to get proper advice about how to leave. When you do leave  it is better to leave gracefully and without any animosity since you do not want to give the soon to be ex employer a reason to sabotage your future. You should remember it is better to decide when to move on than to have it forced upon you. Pay down any debts, save money and have the flexibility of not needing to earn if you are some how forced out. 
Businesses infected with nepotism breed incompetency and have a way of self destructing. Families are wonderful but not all members should  work together.
Good luck with this.