Hamster's testicles Are Abnormal Help please

[Lovely]

They are black and swollen. There is some red as well and scabbing
It feels hard. I'm not sure what to exactly do :(
He's about a year and a few months old.
Pictures for reference. He is eating and drinking, but won't run on his wheel anymore and mostly sleeps.

[souffle]

You must see a vet with him as this could be either a tumour or orchiditis which is an infection of the testicles. It is very painful. I hope you can get him to a vet urgently