Took long enough for my name to come up. I'd have made a poor dentist indeed if I fainted after seeing an extracted tooth, though. After all, in my profession it's far more likely to see damaged teeth than healthy ones. Ok, let's see...
Nothing particularly bad will happen to you if you don't replace your missing molar immediately. Assuming you haven't lost a lot more teeth, your masticatory function, aesthetics, occlusion forces and articulation will hardly suffer at all. Still, if you delay significantly (to the tune of some years), the tooth above and the teeth on either side of your molar will start to move in the space left by it, which can make finding room for its replacement harder.
When/If you decide to do something about it, the most obvious prosthetic choices are either a bridge or an implant. A bridge is much cheaper and takes far less time to make, but it requires drilling the teeth on either side of the missing one to fit them with support crowns, potentially wasting perfectly healthy tooth tissue. The implant has a higher survival rate compared to bridges and does not need any teeth drilled (just bone, which will heal), but it takes longer to finish and is really expensive.
Ice cream can sometimes help with dental pain. Its low temperature can relieve chronic pulpitis (a stage at which your tooth's nerves are pretty much screwed and will unfortunately need a root canal) and it's also suitable for diminishing the inevitable swelling after an impacted tooth's extraction. Ice can do the job just as well, of course, but it doesn't taste sweet.
As far as brushing your teeth like a good boy goes, it's not enough to do it frequently. You also need to do it right.
I'm a bit surprised that something like that's happened to a young Finn, though. I've heard that dental health in Skandinavia is top notch. Maybe it was just Sweden?
Ok, pardon my intrusion. Back to Off-Topic.