hey man relax. Looks like your seedlings are VERY young. You don't need to worry about nutrients/fertilizers until your true leaves start showing (the 5+ point leaves). As for the banana peels, scrap them! Sounds like you're just growing fungus on the surface (not all fungus is bad) and it could overtake and even KILL seedlings!

Bending can also be a sign of over-watering/bad drainage. Don't love them too much. Slow down and read a few posts on germinating seeds. I just germed a whole bunch and have learned a lot along the way. Happy growing