4-yr-old Macbook on the fritz. . . Is there anything I can do?

I got a Mac laptop either the summer before or after eighth grade, and I am now a senior in high school. Since I’m probably going to be getting a new computer for college in the fall, I don’t want to do anything too expensive, but little things have been going wrong for a while until yesterday when it basically gave up on life.

So little things that haven’t been working – the LED on the charger. When the laptop is plugged in, it will work and not die, but it only charges about half the time. – the disc drive. A lot of the time, when I put in a blank CD to burn, the computer will make funny noises and then spit it out again. I’ve realized that if I tilt the computer, it always accepts the disc, so that’s okay.

Yesterday, I was trying to do a project on iMovie when it started freezing. . . and all I was trying to do was play a clip so I could find the part I wanted to add to the project. Just moving the cursor across the timeline made it freeze and quit. Now it happens every time.

Now when I try to open iTunes, it freezes and quits also. To try to remedy this, I moved all my music onto a hard drive (where most of my music was already) and cleaned out basically everything I could from my laptop. I got it to where there were 70 GB available before there was nothing else I could do. I thought this would make everything move faster, but nothing’s changed.

Also, when I start my computer up, it gets stuck on a blank blue screen for literally five minutes before it gets to the log in screen. And now, sometimes, it will freeze, and I’ll try to force quit and log-out and do stuff like that, but the menu bar at the top of the screen will disappear and the pop-up windows won’t show up (even though I get the voice narrating them).

A week ago, my computer was working perfectly (more or less) and there was nothing wrong. . . All of this stuff has started happening totally out of the blue and I have no clue what to do about it! Safari is basically the only application I can use on a semi-regular basis, so I’m getting really frustrated and a little desperate. I don’t know too much about the inner-workings of computers, so if someone could shed some light on this, maybe offer some inexpensive solutions or troubleshooting, I’d really appreciate it!

And sorry about the length. I figured with a problem like this, the more detail the better, right?