This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
懯 combines 敷 (spread, lay out) with 心 (heart/mind). The exact historical development is uncertain, but it likely relates to thoughts or feelings associated with spreading or arranging.
The top 敷 suggests spreading or laying out, and the bottom 心 is the heart. Imagine spreading out your thoughts or feelings, but since the meaning is unclear, treat it as a heart under something spread out.
For フ, picture spreading out a few (フ) thoughts from the heart: few -> フ, and the heart 心 is under the spread-out 敷.