Iphone4 ios downgrade from 7.1.2 to 6.1.3

Hi ,

I am in a pathetic situation because of the upgrade i did on my iphone4 from 7.1.2 to 6.1.3 . The Wifi is disabled, Phone has slowed and heats up quick and within few minutes gets into "Iphone is heated up screen" .

I tried everythingto downgrade and it still doesnt work. I tried with ifaith and i dont have saved shsh blobs. I tried to download the old version of itunes(9/9.1/10.2/11) still it doesnt work .

Any help will be highly appreciated as iphone is literally unsuable. I dont understand the stupid reason for not allowing downgrade