I deny your false interpretation that my God referred to Jesus.
You can deny the truth, but it won't change that "my God" is used in reference to Jesus in John 20:28.
1. BDAG (3rd Edition): Concerning John 20:28 states that theos "certainly refers to Christ" (theos, page 450).
2. A Greek and English Lexicon of the New Testament: Of
the Logos, who is declared to be ho theos, e.g. John 1:1...also in the exclamation of Thomas, John 20:28. - So Christ is called ho theos (theos, page 334)
3. New International Dictionary of New Testament Theology (NIDNTT): Jn. 20:28 contains the unique affirmation of Thomas addressing the Risen Christ as God: "My Lord and my God [ho kyrios mou kai ho theos mou]." (2:81, God, J. Schneider).
4. Theological Dictionary of the New Testament (TDNT): the Risen Lord discloses Himself to Thomas, and the astonished disciple exclaims: ho kurios mou kai ho theos mou (Jn. 20:28). In Jn. 1:1 we have Christology: He is God in Himself. Here we have the revelation of Christ: He is God for believers. (3:105-106, theos, Stauffer)
5. Vine's Expository Dictionary of New Testament Words: Thomas, when he realized the significance of the presence of a mortal wound in the body of a living man, immediately joined with it the absolute title of Deity, saying, 'My Lord and my God,' John 20:28 . (Lord)
http://www.studylight.org/ dictionaries/ved/view.cgi?n= 1705