Assalamu aleykum. I made a du'a against someone few times. I was in a bad state of mind. After some time I prayed for Allah not to accept that du'a and I did taubah. I started having fear that maybe the harm will fall on me and not on that person. I don't want to suffer and I don't want that person to suffer. I also asked Allah to turn my dua's against people into blessings for them. I still worry, what should I do?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If you had supplicated against this person unjustly, then you must seek the forgiveness of Allah Almighty, because what you did was transgression in supplication and it is forbidden. However, if you had supplicated against him justly, then there is no sin on you.

In any case, there is no need to worry at all.

As long as you have changed your supplication against him with a supplication in his favor, then have trust in the Grace of Allah Almighty and His great Bounty, and think well of Him, Glory be to Him, and be certain that nothing comes from Him except goodness.

Therefore, supplicate for yourself and for him with goodness, while thinking good of Allah, and avoiding this anxiety, for it is not justified.

Allah knows best.