I'm in Toowoomba, and recently saw Dr Chamanthi Nanayakkara at St Vincent's when I had my baby. She was fantastic - easy to talk to and happy to answer any questions that I had. She is new to Toowoomba and apparently practices a few days at St Vincent's and a few days through Toowoomba Base. The contact number I have for her is 46 885 621.
I'm not sure on her experience in dealing with behavioural concerns, but hopefully she may be able to help. Good luck