Well it depends on what the online job is and how demanding your physical job is, only you have all the details and only you can find the right balance for them. Having said that, if your physical job does not give you any time at all to spend online and the little time you have is for family, then there is prolly nothing you can do, but if you have even the slightest time to spend on social media, like Facebook, Instagram, etc, you can cut down very well on that, and use that time for your "online work". It is basically about managing and prioritizing time!