、。
Going over it again in my head, it's kind of embarrassing.
Literal
Anew ruminating, somehow embarrassing [emphatic-ぞ].
反芻する ('to ruminate') literally means 'chewing the cud' and figuratively means 'to mull over, to mentally replay.' A vivid metaphor for going over a memory repeatedly. 改めて ('anew, once again') signals revisiting something already past. The masculine ぞ ending adds self-directed emphasis, like talking to oneself. The contraction ~してると (from ~していると) is natural casual speech.