Hi Lea

Borderline cell changes do not mean cancer. The vast majority of sexually active people have had contact with the HPV virus in their lives and for most it causes no issues. Sometimes however it can cause cell changes, which it has done in your case. But borderline changes are the least severe of any cell changes, and at the colposcopy your cervix will be closely examined so they can identify where the abnormal cells are. You may or may not require treatment for this, but if you do it is a quick and straightforward treatment to remove them. Your body can clear the HPV virus-make it go dormant-so it may be that you will not need any treatment at all and will just be recalled in a year for another test. 

Please try not to worry...you have done the right thing in being screened and you have caught very early cell changes which can be successfully dealt with.