I think I have a behav or neuological problem, can psychologist help?

Possibly. Hard to say for certain without knowing the problems that concern you. Psychologists are trained to recognize different kinds of problems and should be able to help sort out whether what you are experiencing is behavioral or has a neurological aspect to it. If the latter, you may need to see a neurologist or psychiatrist. The key point is: get help, if you're worried.
Yes, they can. Help determine if the problems appear to be emotional or neurological. If they are concerned about the latter they will refer you to a neurologist.
Different field. Neurological problems can be effectively diagnosed by neurologists, and neuropsychologists. Behavioral problems can be effectively diagnosed and treated by psychologists and social workers, and psychiatrists.