Say three times:
أَسْتَغْفِرُ اللّٰهَ
I ask Allaah for forgiveness.
'Astaghfirullaaha
Then say:
اَللّٰهُمَّ أَنْتَ السَّلاَمُ، وَمِنْكَ السَّلاَمُ، تَبَارَكْتَ يَا ذَا الْجَلاَلِ وَالْإِكْرَامِ
O Allah, You are Peace and from You comes peace. Blessed are You, O Owner of majesty and honor.
Allaahumma 'Antas-Salaamu wa minkas-salaamu, tabaarakta yaa Thal-Jalaali wal-'Ikraam