You’re absolutely right about depression and anxiety being components of many different disorders including some primarily physical conditions. Most therapists will be able to help you arrive at an actual diagnosis, if that’s important to you. Actually, though, the diagnosis often doesn’t matter much in terms of treatment and in my own work with people, I seldom even think about what their diagnosis might be. The important thing is to find a therapist who will work with you in treating your symptoms and helping you find some relief.