If you are in danger, please try to use a safer computer that someone abusive does not have direct or remote (hacking) access to.
If you think your activities are being monitored, they probably are. Abusive people are often controlling and want to know your every move. You don't need to be a computer programmer or have special skills to monitor someone's computer and internet activities - anyone can do it and there are many ways to monitor with programs like Spyware, keystroke loggers and hacking tools.
It is not possible to delete or clear all the "footprints" of your computer or online activities. If you are being monitored, it may be dangerous to change your computer behaviors such as suddenly deleting your entire internet history if that is not your regular habit.