It is not a serious condition. It is a simple fistula in ano. Please don’t be worried.
Sitz bath and the cream will avoid worsening of the condition and will reduce your symptoms but it is less likely to provide cure.
The surgery is not an emergency. You can try non-operative measures now if you’re not ready and consider the procedure later.
Health Tips
Final decision to operate on a fistula does not only depend on the trans-rectal USG report. It depends on multiple factors and clinical examination findings. Hence, consider the advice given by the surgeon you have consulted. You may also consider visiting another surgeon for a second opinion.