If you have a second computer that works reliably or have a friend, neighbor or relative that you can get to help you, you can use an offline scanner that may help.
What is Windows Defender Offline?
Is one I've use with some moderate success. Just grab the correct version for the system architecture you are going to run the offline scan on and use it to create a bootable CD. Boot the system from the CD and run a
FULL system scan (program defaults to Quick Scan so change that).
See if that helps. If it get's you back in running shape I would still follow up with safemode scans with MalwareBytes, Super AntiSpyware, and SpyBot Search and Destroy, just for peace of mind.