Being pulled like a wishbone

The mirroring is a very strong idea and effective , and the tighter the better. I would have the two stanzas the same number of lines, to give it an equality in that way, if possible.

I love the similarity you've drawn between the clenched fists and the self embrace!

I agree on "effort" although I understand it tends to be part of the connective tissue..and the -trying- rather than the doing is the thing......Maybe there could be a question there...something like "Do his clenched hands stop the surge...?"-and perhaps another question in the final stanza that mirrors that?

You have really created a very powerful emotional piece, that last line of the first stanza is perfectly put, and gripping--as Leanne points out.