Testicle cannot be enlarged due to obesity.
Most probably the scrotal skin might got enlarged and looking big .It can be due to obesity.
If you want to get it reduced,Scrotoplasty
can be done and reduce the size of it.
I am sorry that i do not have any idea of fund raising programme.
If it is not causing any problem,you can leave it.
Anyhow,consult a surgeon/Urologist
Wish you good health