My 14 month old son recently started acting scared of dogs and other things such as certain toys. He has always been sensitive to sudden loud noises, which has worsened recently. He is fine with our dog, who is very little. But any other dog he starts crying hysterically. Additionally, he has started screaming when I drop him off at church and our gym's nursery and usually doesn't stop until I return. Up until a couple of weeks ago he never resisted being left. Should we continue exposing him to all these things or try to limit any of them in any way?