Pepe,
Don't give up. I agree with LOAD_IT, if you don't like the backoffice work and can afford to hire someone to do the paperwork for you, do it. What I have notice is that company drivers jump into being an O/O or Motor Carrier without understanding that it's a business, no matter which option you choose. You are going from employee to business person then they get so frustrated with operating the business. Being an O/O or Motor Carrier is more than just driving the truck.
Pepe, even if you run for Landstar, it is still a business. You still have to get to know their system in order to do well. Hang in there! You have plenty of support here.