How to be more

This is bound to be a long post, and I apologize for that.

I’ve always been very timid due to many reasons, but I started opening up during the last few years of high school. But apparently this is not enough for me, nor for others.

I am, for the most part, basically very boring to be around, with very little charisma or humor, and I seem unable to keep people interested in me. I bland into the background, get extremely overshadowed by everyone.
This is not a constant in every situation:
with other females, especially acquaintances/strangers, I do very well and borderline “the leader of the conversation”. As time goes on and the relationship continues, the king reveals his nudity and they find out my true self.
With males, there isn’t even a first good introduction, 90% of the times. I get flat out ignored, with anyone of any gender around. It doesn’t matter whether the other girl has more personality or not, or if she’s prettier or not: the result is the same. They won’t even answer my questions or accidentally glance at me.

I barely feel like a person, it’s like I am not there at all.
Sometimes I get lucky, and someone will initially pay attention to me, but when they find out I have better, more interesting friends, I get replaced and become second.

I’m tired of being second and straight up ignored.

But I don’t just want not to be ignored, I want to be really good, and I’m aware this can come off as arrogance, that you will all probably harshly criticize. But I believe it’s fair to tell you that.

I’ll add some more information:
1. As you might have guessed, I am a female;
2. I’m almost a legal adult and I go to high school in a smallish town;
3. Yes, this is almost for certain about my appearance. I’ve always been ugly, but I do consider myself around average now. So it definitely plays a role, but it’s my lack of personality, I believe.
4. I used to be quite awkward, but I’m much better now. Though I do still find it hard to keep the conversation going and not boring, of course;
5. I’m mostly around guys, because thats my class’s demographic, so I can’t really change atmosphere;
6. Following that, I am not American. I only have those as classmates;
7. When I’m around other people, I typically do better, but it ends in the same way if the relationship progress.
8. People around me are a bit vulgar, but even those who aren’t, don’t find me as pleasing as I’d like. (As I would like = come up to me and talk, just like they do with others. No, I don’t look intimidating nor unwelcoming).

So I’m here to ask for help, not really empathy, though I won’t reject it of course.
How do I stop being a social failure? Please don’t tell me to chance my mindset, I know the consequences of not being accepted or considered inferior. How do I do better? Change myself? How?
I don’t think it’s about not interests, though they do contribute, more about pure personality.
Thank you in advance. I know this is hard to answer, but If i didn’t think this wasn’t serious, I wouldn’t be writing this.