Never skip a study time. Always sit down at your station at study time. Do this even if you don’t have pressing homework to complete. Keeping a regular schedule will help prevent procrastination. If you find yourself sitting at your desk and looking at your books, but not reading, remind yourself that you only have to study for a short amount of time. Set a timer. At the end of that time, close the book and give yourself a break.
Make sure your computer is protected against malware. If you have Windows 8 or 10, you should already have Windows Defender (but make sure it’s on and up-to-date). For further protection, you can pair that with the free version of Malwarebytes. It also doesn’t hurt to install an ad blocker like Ublock Origin (which is what I use in order to block malicious ads before they even get the chance to load – you can always whitelist the sites you trust if you want to support them.