I know how it feels to get that letter! I totally went to pieces when i got mine, it was the first time I had had any kind of real worry about my health and I think the fear and panic is a natural reaction and like most google was my first port of call. I think that is a double edged sword though, knowledge is good as it helps to understand what is happening to you and to be honest the advice leaflets I got didnt contain much information, they are also very concise so the info often comes off as very medicalised and a bit scary. The problem with the net is that its often full of rubbish and outdated info, not to mention all the scare stories, granted some have bad experiences but more people post about those than positive experiences giving a very unbalanced representation of the true picture.
If you feel you need more info stick to Jo's or other more 'official' sources of information, you can always ask questions on here and for anything the ladies here cant help with there is the 'ask the expert' facility.
If your results are high grade then it is more than likley you will need treatment and thats not meant to scare you, in fact its a good thing to get rid of any abnormal cells before they ever get the chance to become cancerous and the treatment really isnt that bad. I was terrified but it was all over so quickly and i think I had built it up into something way worse than it actually was, my treatment isnt over yet though so that opinion may change lol.
Nobody can say what your results will be but one thing i have learned is that there really is no point in overthinking the 'what ifs' I have driven myself crazy more than once thiking about all the possibilities but have now come to the conclusion that I will deal with things/results as they happen.
good luck with your colpo and let us know how you get on. Feel free to ask any questions no matter how silly they may seem.