Letter to My Geirus Rabbi

Hi Rabbi Posse,
I used to be pretty Jewish, and then I got mad at Judaism because of the people who often times represent it poorly like the following bright , and pure young man I’m about to mention. And then I became kind of jewisher again for a number of reasons . During my hiatus from jewishland I mingled with sheigitses . Upon return to dating Jew boys I encountered the aforementioned young gentleman who forgot to tell me he’s a Cohen. Let’s say he went to the store and tried on the shoes without having any intention to buy them. I haven’t spend too much time in shiur but I think that’s a no no . I’m also not the only pair of shoes he’s tried on , nor the least Jewish,  if you get my drift. At the end of the day it turns out that I’m classified as a whore unfit to marry this clearly super holy and pure guy.
The thing is, there’s a lot of different perushim regarding that hallacha, some deeming that a woman who had relations with a non Jew is invalid, others saying she isn’t , some even get down to whether or not contraception was used and , some say that even if she is invalid the children can still be cohanim and others say they cannot .
What was the original hallacha, who added my brand of “whore” to the list and why , and where do you stand on this issue?
I’m not marrying this particular idiot , but I want to know whether I should do like the other semi-secular Jewish girls and just lie about it like they lie about their virginity or if I stand a chance by just being that thing…what’s it called again?
Ah yeah…honest