Self Esteem Hurter

Yeah, that didn't help. So I don't have great self esteem. I'm a big guy and I have been for most of my life. I'm the nice buddy buddy friend who apparently will always be a friend. I'm a guy just like every other guy out there. Maybe I am nicer than most but I have feelings too. Hearing that more than one female cannot see me as more, as in the sexual sense, kind of cuts deep. It's like that is just BULL. If I flirt, it should not give a woman the creeps, especially if it is the tame kind between friends because mainly that is just TAME. It gets a little old when ladies only see me as a little brother. I used to get LYLAB all the time in high school. LYLAB = Love You Like A Brother. That is not what any guy wants to hear except from his siblings because that is the only place it should be coming from. How does someone get rid of this reputation? I'm an adult and I cannot shake the image of being the little brother to women. It is a load of crapola. Should I stop being a nice guy and just be rude and obnoxious all the time? I like being nice, I'm a nice guy, but it does not get a person all that far. How does someone deal with this stigma? I'm at a loss. Feel free to actually answer the questions in this post. Feedback is appreciated.