As you're work only online, with having insomnia you don't have to worry about it affecting how you work in the office. By working at home or from home, there will be a time when your body will want to shutdown. If this happens, don't try to stop it. Stop everything you're doing and sleep it off.
I have worked an offline job around two years ago. At that time, I never felt this problem because I used to work a night shift. I do not feel sleepy at night and this is one of the main problems. I feel sleepy during the day time when I am supposed to work.