The ECrtHR does not have the power to overturn UK law or rulings nor can it force a sovereign nation to change their laws.
The supreme court rulling was already tested in FWS vs SPS where the SPS put forward human rights claims of trans identifying males under articles 2 and 8. The SPS had their arses handed to them it is not a human right to use opposite sex spaces or facilities and women have human rights too.
the ECrtHR have recently refused to get involved in multiple "trans rights" cases that have failed in the UK supreme crt including the American man who wanted to force the uk to recognise nonbinary gender and allow passports and birth certificates to be issued with an X and the woman with a GRC who wanted to be registered as her children's father on their birth certificates.
Even the multiple attempts to have the ECHR lose its A rating failed.
You really need to understand that the time of trans activists being able to bully, lie, misrepresent the law and use threats of a higher crt are over. Women have human rights too and everybody now knows that women's human rights are incompatible with the demands of trans activists.
your only way forward now is with primary legislation that strips women of all their human rights and you will have to campaign for that and explain why the wants of trans identifying males should override the need of women and girls not to have grown men in their single sex spaces.