treatment of symptomatic fibroids differ depending on the age and completion of the family etc,
in case of minimal symptoms the hormonal
pills can work, if the pills are not working then the next treatment options are intrauterine device
or finally hysterectomy
so as medical treatment failed you can go for mirena as told by your doctor which possibly help but in case of irregularity of the uterine cavity
due to fibroids the coil may not stay but as you are having only intramural fibroids probably mirena will work, use antibiotics along with this for pyosalpinx.