I would ask for an appointment either phone or face to face with the GP at the practice who knows the most about menopause and women's health.
Explain frankly to them the problem you have and that you have chosen to use daily vaginal estrogen to adequately treat your GSM, in accordance with the BSSM (British society of sexual medicine) guidelines on this.
It would be helpful for you to hand them a printed copy - the guideline has been shared on this forum previously and can easily be found online.
If they are unable/unwilling to prescribe this, request a referral to the local NHS menopause clinic.
Often the menopause specialist will just email back and say if course you can use daily estriol, without needing to wait for an appointment.