Before. [Comments Welcome]

[Anactoria]

How will this situation or feeling change if i hurt myself?
It probably won't. I guess it'll only make me feel worse.

What will hurting myself bring to the situation? what will it take away from the situation?
It will bring more questions about injuries and more having to cover up. I think it'll take away the horrible thoughts and some of the internal pain, as cliche as that sounds. It will make me hurt a little bit less on the inside.

How do i want to feel about this in the long run? is hurting myself likely to get me closer to or farther from feeling that way?
I want to be better. I don't want to always be hurting and always be in pain. I don't want to have to hide anymore. I want to be able to educate people and prove that there is a way to stop; maybe giving someone else the hope that I haven't recieved yet. Hurting myself now will definitly bring me further from that goal. I know that. I'm going to be a month free on Friday.

If hurting myself seems like my best option right now, how long will the relief it brings last? what will i do then?
It'll last probably only ten or twenty minutes, before I fall asleep. After that... well, I'll sleep, have to take care of everything, and then wind up feeling guilty. And stupid. It's not something you can easily explain to someone when they ask you why you're feeling down.

What is something i could do now instead of hurting myself? how will it change the situation i'm in? how long will that change last, and what will i do then?
I could study or just go straight to sleep. It will make me feel better, but it won't change the situation I'm in. I just feel very lonely and loveless right now, since there is currently a guy I like that I won't make a move on because I'm scared. I don't even want to hope because then I know I'll wind up being hurt. The only long term change I could think of would be to talk to someone else about this.

How will i feel tomorrow if i hurt myself? how will i feel tomorrow if i do the other thing i came up with?
I'll probably feel pretty bad tommorow. I won't want to get up, or do anything, but I'll have to go to school anyway. I'll have to hide; I hate hiding but I hate the idea of people knowing. I'll probably feel much better if I just go straight to bed or do more studying.

What do i really want to do right now? how can i best honor the self-protective instinct that has me wanting to self-injure right now?
I really want to stop liking this boy or tell him how I feel. That's not really an option now; it's too late and I'd never be able to do that anyway (tell him, that is).

I think this helped, a little.

[5th section]

Well, I think it's clear from what you said to the first 2 points that you don't think of SI as a real solution - I think the first important thing is not to lose sight of that.

It'll last probably only ten or twenty minutes

keep that in mind, i know that might be difficult but it might help you see that the relief it brings doesnt last.
so about the long-term situation...

I could study or just go straight to sleep. It will make me feel better, but it won't change the situation I'm in. I just feel very lonely and loveless right now, since there is currently a guy I like that I won't make a move on because I'm scared. I don't even want to hope because then I know I'll wind up being hurt. The only long term change I could think of would be to talk to someone else about this.

From all this it seems you actually do know what to do but for some reason don't want to or can't go through with it. possibly you're worried you've got too much to lose (?). but I don't see that you'd lose anything by talking to someone else (not to this guy directly, at least not at first if you're not comforablte with it) and then at least someone can give you support & advice.
Do you know who you would talk to & what you'd say? maybe start planning it more definitely. I can only speak for myself here but i've been in similar situations and it can sometimes help to be planning and feeling like you're doing something, instead of the feeling of powerlessness that can make SI look like the only way out.
dunno if this advice is any good but I can certainly relate to what you're saying so i thought I should offer something. take care of yourself.