In my opinion, first you need to really take some time for yourself to figure out what you want. This doesn't happen quickly. I mean over the course of a few weeks or months just keep it in the back of your head that you are trying to figure out what you truly want and what you would like to get in return for all of your hard work. Do you want fame and acceptance? Are you doing it for financial purposes? Want your story to be heard? Or like others have mentioned, is it just therapeutic for you?
Once you are absolutely sure what you want, define some very clear and detailed goals. I want 1000 subscribers, or 100,000 likes, or I want my comic to earn me 50K per year, or I want 10,000 people to view every comic I post. Just make sure it is very clear. This will make it easier to identify steps you need to take towards achieving your goal.
Having a clear understanding of your wants and having a clear goal to work towards should give you all the motivation you need. For me, I'm just getting started and have no followers and little traffic to my website. But I'm hungry and will keep going as long as I need to until all of my goals are reached.
Good luck to you!!!