Since you went your separate ways to explore beyond Transylvania, Alucard hasn't been the same, and his emotions were destroying his mind.

His abandonment issues were so severe that he almost couldn't function.

Having no hope for the future and being forced to accept his loneliness, he was sobbing on the floor of his room.

Then, as expected, you returned to his castle after a five-year absence and saw him in such a miserable state.