So sorry that you are in this position. It is very scary, I know.
When you go for your colposcopy appointment, they will explain what they are going to do before they do it. I know some women on here had a different experience to me, but I found the doctor and nurse who dealt with me very sympathetic and kind, so please don't get into too much of a state or jump too far ahead with 'what ifs'. This is about finding out what's going on and getting the right treatment.
You lie on a couch of the sort that you would have seen when you are pregnant with your feet in stirrups. I think I wore a long tshirt and stretchy leggings to my appointment so I just slipped off my leggings and pants and pulled my top up a bit. They were very good about covering me up so I didn't feel too exposed. The nurse chatted to me and help my hand while the doctor was at the business end.
They will use a speculum to hold your vagina open so that they can see your cervix and then will use a light and a camera thing to have a close-up look. Nothing apart from the speculum is inside you at that point - the image is projected onto a screen that the doc looks at. They may or may not offer show you too and its up to you if you want to look.
After that it all depends on what they see as to what comes next. They may need to paint some chemicals onto your cervix to help them see what's going on. If you do have a growth they will probably want to give you a local anaesthetic and take a little sample. They may even say they want to do a procedure whereby they remove a larger piece of your cervix (LLETZ) under local anaesthetic then and there or they can do it later under a local or general.
It might be a good idea to take someone with you to take you home afterwards - I thought I was just going for some tests, went on a very bouncy bus and regretted it later! Even if you don't want them in the room with you, you a sympathetic friend who will drive you then get you home safely and make you a cuppa is a godsend.
Whatever happens, the things is to focus on getting more information so you can get treated and get on with your life, whatever it is that you turn our to have.
One step at a time! x