You did say that you love me, but your love seems to be only for everyone. What do you mean?

This sentence means that although you once said that you love me, you treat everyone equally, without special attention or unique love.

This sentence may imply that the other person's love is not true or profound, and it is just a rhetorical device. It can convey that the other person's attitude towards love is superficial and does not really understand and consider the other person's needs and feelings. The other person's love seems to be a universal emotion, without special pertinence, which makes people feel that they lack a sense of importance and uniqueness. The whole sentence may be dissatisfaction or doubt about the other party's expression of love.