Tasallat is connected with the root s-l-w (س ل و), which involves recovery from sorrow or the fading of emotional attachment. Munsal also expresses separation or withdrawal; here it means a heart that has not disengaged from love.
Laysa is a defective negating verb; fuʾādī is its subject and bi-munsal functions as its predicate, with the bāʾ reinforcing negation. ʿAn hawāki identifies what the heart cannot leave: “your love.”
The verse opposes tasallat (others have recovered) to laysa ... bi-munsal (I have not). This contrast in conditions supplies a personal conclusion to the preceding catalogue of admired qualities.