I think a large amount of attraction is based on the amount and type of exposure we have to another culture.
From my own experience; I'm now mid 40's but I grew up went to school in a very white, middle class enclave. And that's the type of man I was attracted to. However, as I've gotten to know people from other cultures, their features become more normalised to me and I start to see attraction where I didn't previously.
I think also the media has a bit to do with it. The more we see people from other cultures on film, the more their looks become normalised. For example, Naveen Andrews is really hot and his looks broadened my mind to appreciate other men who have Middle Eastern looks. Likewise Steven Yuen (The Walking Dead) has really opened my eyes to Asian men.
I think that getting to know the guys would be a great start for you. Let them know you as a person instead of judging you by your appearance.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.