ANSWER:
You did the right thing by repenting to Allah and breaking up with him! This doesn’t please Satan and this is why he is doing his level best to get you back to sin and to make you anger Allah more and more so that you and satan would be in the same boat.
Part of your repentance is to never get back to such sins again. Therefore, if you want Allah’s forgiveness, you must not ever think of that person at all and pray to Allah that He sends you someone who is righteous and practicing as a husband.