Bismillahir Rahmaanir Raheem
Al Jawaab Billahit-Tawfeeq
If you made an oath to Allah, and it is broken; then you will have to give Kaffarah (expiation). Kaffarah is feeding ten poor people two meals or clothing them; or if this is not possible then fast for three consecutive days.
See - www.muftisays.com/qa/oaths-vows/4986-oath-not-to-get-marr...
And Allah knows best