The fear of falling in love.
It can also be a fear of getting into a relationship that you may not be able to maintain.
Everyone experiences Philophobia to at least some degree but in extreme cases Philophobia can make people feel isolated or unloved.
"Lithromantics are individuals who experience romantic love but do not desire their feelings to be reciprocated. Lithromantic people may want to avoid dating and romantic relationships entirely, or may be comfortable with such a relationship or even desire it, as long as their love is not returned in a romantic way. Some lithromantics may even accept reciprocated love, but do not require it to find a relationship fulfilling, as most romantics do."