Im not a Dr or therapist but I would say its likely anxiety. I think you need a event with more trauma to have PTSD. Like being in a war or sever bullying. Bad car crash or something like that. Isolation like you described is not got for your mental health but I dont think it causes PTSD unless its a severe situation like your in solitary confinement in a prison for a long time. Just my opinion but I think it makes sense. See a professional to make sure though.