I've been with 11 women and 10/11 said I was or was one of the smallest guys they had been with at the time.

and there was nothing wrong with that. saying you're small in size isn't always a negative thing, but it can be if you take it that way. being told I'm small or one of the smallest didn't (and still doesn't) bother me because it's factual. I'm still confident in my size, and they take note of that confidence and how I carry myself around them.

They all wanted a Alpha male. How can I be Alpha when every woman has told me I am the smallest??

who said they wanted that? did they tell you they wanted that or is that what you convinced yourself they want?