I am sure study of 1 John is going to repay dividends in respect of understanding present Anglican Communion turmoil, and I am hopeful it might give some practical leads as to how to proceed from here.
But I am conscious that Anglicans on all sides are claiming rights to be identified as 'orthodox' so 1 John may be (literally) two-edged as a piece of the sword of the Spirit. The modern counterparts to the Johannine secessionists could be (for instance) Anglicans leaving TEC or it could be TEC on its present path, which some commentators describe as a 'leaving' of true Anglicanism. Or, we could think of the themes of light and love in 1 John, and read the letter in such a manner that (for example) it is the bishops and dioceses in western USA currently embracing the State of California's recent decision supporting 'gay marriage' who are enlightened and truly loving a fellow Christian in need, and it is those opposing them who are, effectively, denying 'Christ', living in darkness, and 'hating' their brother and sister Christians.
Incidentally I have a book on 1 John on my shelves by one J. Darby, which is a reminder that in the past 1 John has not only served the cause of secession from the Church of England in a 'Brethren' direction, but also justified a continuation of such secession into an 'exclusive' ecclesiology, so that, here in Nelson NZ where I live, we have many Exclusive Brethren!
How to proceed? The only way I know is to engage in careful but also just study of the text, with an openness to rethinking any current belief in the light of that study of Scripture.