Trojan

Hello,

So my computer has been taken over by viruses and trojans. I was unable to run a scan so I entered safe mode and did my scan, It took 2 hours and found like 20 issues at the end of the scan I clicked end like I nornmally do. This is when the computer prompted me to restart so everything could work. I allowed it to restart and now I am unable to get past the log in page. So I can not even get on to the computer to attempt another scan. Help me please, I have so many important school work on there and I am a student and can not afford to take it in to get fixed. Any suggestions?