I'll try tackle this one, though I should preface that Cohen's lyrics are often impressionistic, combining different motifs without one specific meaning. For example, "Hallelujah" - perhaps his most famous song - combines different Biblical stories (David, Samson) freely, not being easily mapped to one single character.
This song combines different motifs, too. Your interpretation of "you strike my side by accident" could well be correct. This song appears to be partly in the voice of the soul entering the world (the "Avalanche"), partly in the voice of the Deity, and partly in the voice of a scorned lover.
Here is a good thread discussing these and other aspects of the song, such as Gnosticism. Here is some more from Quora. This is an academic paper discussing, _inter alia_ , Cohen's original poem that this song was based on. (I've tried to summarise these sources in this answer, but they are worth reading for further depth.)