The people telling you you are infected could be wrong. There are infections out there that can attack anyone who just happens to have you on their mailing list, possibly a friend and it sends out messages spoofing you as the sender. Change all mail, Facebook and messenger passwords.
Post your HJT log on a specialist forums, we can't read them here:
Be sure to read all the sticky announcements/instructions at the top of each malware forum!
Meanwhile you might want to run a scan using the FREE version of THIS tool. Update it before running. If by any chance the infection, if present, stop that tool from working, all that can be done in Safe Mode with Networking, it works.