Is it possible that a guy can't reach his G-spot (prostate gland) using his 2 & 1/2 inch finger?

I've tried to find my own G-spot through inserting my mid finger and observing if there's a walnut shaped something and if i feel ual pleasure after I've touch some part. But, I have failed. I felt very hard on finding my G-spot and what I've just done is to in the common way. I haven't used lubricants as I heard that lube should be the only lubricant that is used for prostate milking. What I only have is lotions that's why I was disabled to use any lubricant.