This could probably go here or in the "In search of.." but i think here may be more appropriate.

I have a bad crush on a friend of mine. It's bad because I feel like it's kind of destructive. I've never been good at expressing my feelings for someone else, and so I haven't told her. But I feel like it's not just having a negative effect on our friendship, but my whole social life.
Our friendship is very cyclical. For a week or two at a time, we'll be really close, hanging out a lot and doing stuff together and making each other laugh, and it's those times that really make her attractive to me. But then, for a week to as long as 3 weeks, she'll disappear on me, hanging out with her cooler sophomore friends and barely acknowledging me. Even when I try to be assertive, and make a real effort to see her during these down cycles, she's just never around. It's these periods where I start thinking about her constantly, alternating between longing and anger, to the point I can't focus on my other friends or the rest of my life. I'm pretty sure she's not into me, and I'd rather start exploring elsewhere to find a girl, but I can't get her out of my head. When she comes back eventually, I'm happy again, but I still feel weird for not being able to have a normal friendship with her.
I want to solidify our friendship. I'd rather be her close friend than tell her how I feel, and risk losing her completely. Sometimes I just think about ditching her completely. But when we're getting along it's hard to follow through with that. She's one of the most beautiful people I've ever met, not just in looks but in her personality.
What do I do? Tell her how I feel? Ignore her completely? Keep going what I'm doing? This is taking up too much of my thoughts, and I really, really want it resolved somehow so I can move on.

[moimeme]

Your plan to be just friends would be a fine plan - but thinking about her all the time does not constitute friendship so, while your plan sounds fine on paper, it's not working at all. What you need to do is find other women to spend time with, one of whom may become a girlfriend, and then perhaps being just friends with this other girl might actually work.

[Indie]

I'm going through the same thing and I think the advice you just got sounds like something I will try