What you are doing is called a dimensional analysis, that is you try to determine the physical character of certain quantities (units). Your problem is in the proportionality factors, more specifically: [W] = [I2 R T]
[V] = [I R] = [I (W/I2T)] = [ W / T I]. So, everything is OK dimensionwise. Will voltage in a resistance circuit decrease with I? No, because W is proportional to I2, so V α I.
Tunc
(published on 04/15/2015)