"I'm constantly trying to be really nice to her and treating her like she's on a pedestal".
That's what most guys do, perhaps hence the 'nice guy' concept. The problem is that 9 out of 10 guys treat her this way, so how is she suppose to feel special?
One day he buys her lunch, next day he buys her tickets to movies, the next day he pays for whole trip. He always does things for her. Then he marries her, buys her a ring, house, cars,... He always smiles at her, never gets mad or upset. She's bored with guys who have this attitude, she doesn't feel special at all no matter how many nice things you do for her... She simply doesn't FEEL anything with this guy, she got used to the niceness-ness, and there are no other emotions...
So stop being nice to her and any other girls. She may have a pretty face and nice body, but she is just a person. If some girl was constantly nice to you, and constantly doing nice things for you, constantly smile at you - would you appreciate her? Maybe first 2 weeks, then you would get bored. Week later you would get quite annoyed with her, and another week you would get depressed because she is so boring with her niceness-ness. Another week and you want to run away, very very far from her... If you were so fortunate and marry her, a years later you would start drinking because you couldn't stand it, you would want to forget your boring life. How is it possible, she is so nice and so sweet - but I just can't stand it?
Now imagine a girl that has a very good vibes with you when you meet her, you are in seventh heaven. You feel so important because she pays all her attention only to you. But second day she doesn't answer your messages. You get all anxious, all worry... You sweat and you bite your fingers because you can't stand it. What happened to this hot girl? You call her her another four more times just to make sure she's got your message. You leave your phone numbers, emails, fax number and FB link, just in case she misses one - but nothing, still no answer... Your life just collapsed, there are not tomorrows...
Then she calls you two days later and maybe invites you out... Sorry, I didn't feel good, she says and giggles. You are in seventh heaven again, your emotions skyrocket, your heart beats in excitement. Nothing happened, you say, I was just really worried about you. So you go see her again and she is all excited to see you, she makes you feel really great about yourself... you feel like a hero who could save the whole world, all she has to say is: Do it for me my superman! ...
But then, another day later, you pretend to walk into her randomly and she acts as if she doesn't know you at all, she just looks through you as if you were nothing... What date? she's looking at you as if you were a weirdo. I don't remember you, you are just another guy I was flirting with, there were like 40 annoying guys like that just this week... So you emotions drop below zero, you are all freezing, feeling miserable about yourself, you are insignificant again... But three days later she is hot again, all over you, she calls you for a date, buys you a coffee and apologizes with giggles: Sorry, I had a terrible day. She then tells you how special you are - just to show you the next week what a bitch she is...
And you are becoming desperate to get this girl because there is just something about her... the more you know her the more you want to be with her, she is such a cute bitch...
True, she could be a psycho, but it also could be a plain hot/cold game. She is rocking your world, she is rocking your emotions: up and down, hot and cold, close and far, left and right - and after a while you forget everything except her...
Girls are even more sensitive than guys, perhaps that is the reason why Nice Guys don't get many chances, if any at all... They are just too boring with all the niceness-ness, there are just no emotions involved...
So you want to rock her emotions. One day you do something nice for her, and the other day do nothing, when she asks you to do something you say NO. You make her feel great one day, and then you go cold, distant, you don't call back. You piss her off one day, then you bring her flowers. One day you take her to comedy center so she laughs her ass off, and the next time for some drama movies, make sure that she cries for a while. One day you take her on a roller coaster so she pies in her pants with fear and excitement, and another day you take fishing, and you fish and fish til she gets bored... You piss her off one day, you make you hate you - and the next day you make compassionate love with her...
You simply make her FEEL, and the more she feels while around you, the more she feels special...
No need to go overboard at all, the above is of course exaggerated, and you also want to remain emotionally stable yourself... If she calls you a prick one time, and the next time she tells you that you are a great lover, you know that you are doing just fine....