The problem may be that y(v,t) is not a martingale,
but if you multiply y by exp(p(u2)∫(0 to t)vs ds),y*exp(p(u2)∫(0 to t)vs ds) will be a martingale. That's why you miss a term there. (Just my first glance, perhaps not correct).
If you have trouble for verifying that y*exp(p(u2)∫(0 to t)vs ds) is a martingale, come back to me.