I think if you put a comma after you in the third line would clear the senryu a little further. Because the way it reads now indicates that you also regret that you yourself were not fooled. Or you prefer to fool yourself rather than fooling the second person. But it isn't okay to fool yourself trying not to fool another person. For fooling any person including yourself is regretful. I think putting that comma would make it more look like the way you were intending. In which means you regretting fooling the second person and announcing that you were not fooled by yourself anyway.
If there is an angle I did not see please advise me because we are here to learn, right?
Anyway I know how scarce it could be to consider all the possibilities in a tiny senryu.
Lovely after all!!