I've raised £250000 to help save my 4 year old's battle with a rare childhood cancer, Neuroblastoma

On 29th December 2018, Mehlyk, a fun-loving, highly energetic boy was diagnosed with a rare childhood cancer, Neuroblastoma, at the young age of 3 years old. The tumour was located in his adbdomen mainly ontop of his left kidney and had spread to his leg, arm, chest, spine and pelvis.
Mehlyk was transferred to Great Ormond Street where he underwent 8 cycles of chemotherapy, resection tumour surgery for over 6 hours in which a large incision was made to his tummy - but only 5-10% of his tumour could be removed.
He then received high dose chemotherapy for 6 weeks a few days after his 4th birthday and an intense boost of radiotherapy for 5 weeks to target the residual tumour.
In October 2019, when radiotherapy ended we received the devastating news that his secondary metastatic disease that initially responded well to chemotherapy had relapsed in his neck, chest, femur, pelvis, spine and jaw.
The prognosis for survival is poor for our sweet little boy and we are now desperate to find the best treatment in order to save his life. We have been advised by various Consultant's that the best treatment would be a combination of chemotherapy and immunotherapy which is accessible in Barcelona, along with a vaccination to ensure he stays in remission.
This treatment is expensive, costing over £200,000, so we are asking for your help. Mehlyk means so much to us and we dread to think of losing him to this horrible disease. Please, Please help us in any way you can.
Thank you!