A drilling fluid composition comprising a drilling fluid additive, wherein said drilling fluid additive comprises hydrophobic, lignin-coated cellulose nanofibrils, wherein said hydrophobic, lignin-coated cellulose nanofibrils are present in said drilling fluid composition in a concentration from 0.001 wt % to 10 wt %, wherein said hydrophobic, lignin-coated cellulose nanofibrils have a cellulose crystallinity of at least 60%, wherein said drilling fluid additive further comprises a crosslinking agent, and wherein said hydrophobic, lignin-coated cellulose nanofibrils are crosslinked to enhance gelling within said drilling fluid composition.