He had fallen in love with her but missed his target. Check Lysander's absurd drug induced appeal to reason 114-122. To eventually bring about resolution, they complicate the plot further. See also line 92. See especially Helena's recollection, lines 201-216, where friends' similarity is disrupted by sexual differentiation.
General exhaustion prevails.
But when you dream you're dreaming, you're closest to waking up. Compare his blessing here to fairy lullaby, II,ii, 9. Contrast how they appear to one another and how they appear to audience. Also contrast their two versions of ultimate pleasure. Compare Oberon's triumph to Theseus'.