You are asking a question which involves both a detailed knowledge of Giddens' ideas, and a sophisticated analysis of "explanation". You are unlikely to get a satisfactory answer here.
From the little I have read it is indeed Giddens' objective to account for the interface between micro (self) and macro (societal) levels of analysis, but I cannot comment on his success in that. One path you might explore (not necessarily that of Giddens) is the idea of "self" as a macrocosm of "society". The epistemological problem with such an analysis, of which you already must be aware, is that sociological descriptions do not sit well with psychological descriptions.
Thank you for drawing my attention to this issue.