As someone who has been through counseling, and with two immediate family members who are professional psychologists, I can tell you that "understanding someone's specific issue" doesn't matter nearly as much as one might think. People have this idea that the counseling process is analogous to a medical procedure: you go to the doctor, describe the problem, they diagnose you, and prescribe an intervention. That is not generally how it works. There is a little bit of that on occasion, but mostly counseling works simply through the process of rendering your feelings into words in the presence of another human being who is listening to you but in whom you are not emotionally invested and who is not emotionally invested in you. That, in and of itself, turns out to be tremendously helpful. (The same mechanism is in play in other kinds of human activities as well, like book clubs, writers groups, or religious gatherings.) You don't have to be black to learn how to provide this service to someone who is.