At 6 months is symptoms intervention the best option for a web b dist fib fx that hasn't healed or can it still heal on its own?

Yes: At six months you can officially declare a fracture a nonunion. You probably just need the fracture edges debrided and stable fixation to make it heal. This entails surgery to put a plate and screws in place to allow for healing. May have your doc consider a bone stimulator too if you smoke or if you do smoke stop before surgery to improve your odds of good outcome.