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.
We did not exactly understand what you are asking about. Perhaps you are asking about a supplication that is specific to your situation; we are not aware of any supplication of this kind.
However, it is sufficient for you to ask Allah Almighty with the general supplications about facilitating matters and relieving distress. For example, you may supplicate with the supplication narrated by Anas that the Prophet said: “Allahumma la sahla illa ma ja'altahu sahlan wa anta taj'alu al-hazna idha shi'ta sahla (O Allah, there is no ease other than what You make easy. If You please You ease sorrow).” [Ibn Hibban in his Saheeh]
You may also supplicate with the supplication of the distressed: “Allaahumma rahmataka arjo falaa takilni ilaa nafsi tarfata ‘ayn, wa aslih li sha'ni kullahu, laa ilaaha illaa ant ... (which means: O Allah, it is Your mercy that I hope for, so do not leave me in charge of my affairs even for the blink of an eye, and rectify for me all of my affairs. None has the right to be worshiped except You)." [Abu Dawood]
There are some etiquettes that must be fulfilled for the supplication to be most likely answered, among which is that the supplicant does not rush the answer.
Abu Hurayrah narrated that the Prophet said: “The supplication of the slave (of Allah) is granted as long as he does not become impatient and says, ‘I supplicated and supplicated but my supplication was not answered.” [Muslim]
If you had performed Istikhaarah before marriage about the matter of that man’s marriage to you, and the marriage took place, then it is hoped that there will be good in your marriage to him.
Hence, our advice to you is that you be patient and not hasten to ask for separation, especially that you did not mention about that man a defect that repels you from him, or harm which you are harmed by so that your seeking Khul’ from him is justified.
The basic principle is that seeking Khul’ or divorce without any sound Islamic reason is not permissible.
For more benefit on supplications at times of distress and grief, please refer to Fatawa 343300, 418060, 88282, 13277, 213715, 265417 and 377509.
Allah Knows best.