Othello Pulls a 180

I just cannot get over such a profound tonal shift Othello has gone through in the past couple acts. He was such a pleasing character in the opening acts, trusting, loving to his wife, etc. Now it is frustrating for the audience (as with most Shakespeare ironies...)to find him constantly skeptical of Desdemona (his ever faithful wife) and trusting of the all evil Igor. Especially when Othello asks Desdemona for the handkerchief that he gave to her and she acts all confused and everything. Well, she should be confused. She hasn't done anything. If anything Othello should question Igor. but alas. it's entertainment and never works out the way it should.