What's the adjective for selfishly? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verb self which may be used as adjectives within certain contexts.
self
Having its own or a single nature or character, as in colour, composition, etc., without addition or change; unmixed.
(immunology) Of or relating to any molecule, cell, or tissue of an organism's own (belonging to the self), as opposed to a foreign (nonself) molecule, cell, or tissue (for example, infective, allogenic, or xenogenic).