It's a great misconception that you are dull. You seem to lack self confidence because you are different. Superman is more "dull" than The Joker. But who saves the world and gets the girl? You have other qualities that are frankly worth more than cool bad boyness. Here's your "scorecard" as I perceive it and it's quite impressive:
"Attractive guy"
Score! Girls like it when you take good care of your looks/clothing
"am very nice"
Score! Since when do girls hate warm, friendly men (don't confuse that with doormats!)? Do read the warning below.
"I am very into my studies too becuase I am determined to become a Nurse Anesthetist."
Score! Girls love it if you're a passionate, driven person.
"I love working out, I like to wakeboard"
Score! Girls like dynamic, active men that do something constructive in their life. You will probably look better AND be better in bed than those drunkards.
"and I'm really into health and nutrition."
Score! Girls like men that take good care of themselves, after all they want a man that can protect them and take good care of their needs.
"love cooking and eating healthy food. "
Score! There are fewer things that women find more sexy than seeing a man cooking. Healthy food = better sex!
"I seems like most guys are just out to "get some", but I actually want a real relationship."
Score! Girls want this too.
"I always fear girls will think I am weird or a "health freak". "
PROBLEM. You're not a freak, just healthy. Remove the freak/weird part out of your mind. Superman is not a freak. The reason you think this is that you're so different than most of the slackers and losers that form the majority of college kids.
"I'm the kind of person who just likes to hang out and talk for hours about whatever, but lack the confidence to start a convo with a girl. Could I actually be intimidating to girls? I just dont know. Is this quiet nice guy/dull guy image killing me or am i just paranoid?"
PROBLEM. It's not paranoia, but lack of confidence and nice guy get in the way of what you want.
First step is to approach girls. I too have a hard time finding good openers, that's because there isn't any. Just ask their opinion about something or give them a critical compliment, like "I like the way you did your hair, I've seen 3 other woman today with that haircut" (this is called a "neg", not an insult but something that shows your lack of needyness, it's important that girls don't get the idea that you are hitting on them). You can say the same about clothing, fake nails, small imperfections, the hotter the girl the more negs you'll need. Second step, when you talk to them (you'll need to thrown in multiple topics and not stick to one) ask them about what dreams they have, their ideal vacation, relationships, friendships, emotions, girl stuff! Start reading girl magazines for all I care.
There's more places to meet girls than you think, more than parties and clubs. You can approach girls between classes, fitness, on the street, the grocery store, maybe even try the library where you don't have to scream your lungs out. It's also less scary to approach a girl when she is alone and doesn't have her posse with her. But don't be afraid of those posses they will eat out of your hand if you come up with enough confidence and engage them in conversation.
Here's a warning about being nice. That's also why you need negs.
Nice guys don't get laid, they stay in the friendship zone. The reason: they're too polite and don't take the initiative fast enough to (in this order) 1 touch a woman 2 hold her hand 3 kiss her mouth 4 kiss her neck 5 gently touch her breasts 6 use your imagination what's next. You have to fight for your values, say no to alcohol and be proud of it, say no to things you don't like, they'll respect you for it and if they don't than try to find more intelligent company. Have your own opinion, be your own man and stop trying to please women all the time. Mr Nice Guy sometimes will have to be Mr Alpha Male. You're the cool person, you're the prize.
That's also why you can't be too available. It can help if you say stuff like "I have to go in a sec and talk to my friends but I have a question for you."
Women will love you. You're getting advice from a total newbie that still has to apply these things. Read Mystery Method or other dating gurus. Buy those pickup artist books. Try to learn what I'm trying to learn. I'm 30 and never got laid (but I guarantee you I will). I have only begon to discover the secrets of the female psyche. I am struggling with the same problem as you but I know what to do. It's the stuff you don't learn from your parents or at school. Maybe because it's too powerful and they don't want you to get laid like crazy all the time.
Women, be grateful for guys like this.
And people need to learn how to spell here!