All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
That man has become a non-Mahram to you, and if your heart being attached to him does not lead to a forbidden matter, then you are not sinful; for more benefit, please refer to Fatwa 89266.
Besides, it is permissible for you to ask Allaah to make it easy for you to remarry him; so you should not despair as Allaah is Omnipotent and everything is easy for Him.
So, if your marriage with him is facilitated, praise be to Allaah, otherwise you should not be attached to him. Rather, you should ask Allaah to bless you with a pious husband as there are so many men.
It should be noted that it is permissible for a Muslim woman to look for a pious husband and it is permissible for her to propose herself to someone whom she wants to be her husband provided she abides by the Islamic conditions in this regard. For more benefit, please refer to Fatwa 82471.
Allaah Knows best.