I think the easiest way to keep going is make sure you're having fun. Sure working on something can be grueling sometimes and feel kind of pointless, but if you're enjoying yourself then it'll be easier to make time for doing it.
If working on your comic isn't fun or satisfying anymore, then revisit your reasons for starting it. Was it to get recognition for your work/make a living/improve your skills/tell a story you really wanted to share? No matter the reason, think back to it and see if you can make that a reason that drives you again.
Before you decide to cut your losses with your comic, think about how you'll feel about it in a month's time or even a year's. Would you wish that you stuck with it a bit longer or would you be glad that you got rid of a weight that was just dragging you down? It really depends on how you see your comic. There's always the option to move away from it for a little while and come back and recreate the way you originally intended (if it isn't living up to your expectations right now).
Ultimately, if you do stop with your comic, I don't think you should stop drawing entirely. You never know when a skill can come into play in your life. If you keep practising (so long as it isn't a chore) then you might find a project that you can completely engage with. Who knows, by then you might have more time to dedicate to your art.
Summary: Find what's fun about art, whether that's making your current comic or doing something else, just don't stop drawing because of time restraints.