He doesn’t have to befriend a therapist or expose his life to him. All he has to do is tell how he is feeling in a current situation. A therapist will only guide him a new positive perception of thinking. You can for sure give him warning that if he isn’t ready to cooperate in any way, you won’t cooperate either. Don’t force him but make him get out of his comfort zone at his own will. He might fear that therapist might tell his personal things to you which might also be a reason why he is hesitant that’s why it is important for him to see and meet as well. If not then tell him to change his view at life. You can start his therapy by appreciating his subtle gestures and notice if he starts to respond and reciprocate. If he doesn’t then involves yours and his parents because this matter needs attention and he needs to get out of his bubble of insecurities. Also be look out of yourself in this process too. Maybe you might swayed away of pressurising too much that you might not notice. So its better to keep a balance and hopefully good things will come your way