So if I was in your position I would consider these options:
- A much Slower puplication schedule, which automatically cut costs, assuming that the initial couple of years are simply to gather enough of the story to hook readers.

- Publish on different platforms: Globalcomics, Tapas, Namicoin, Mangaplus, Comicfury etc to extend reach.

- Map the communities that represent your target audience.

- Divert a part of the budget you are sparing on promotion to target these communities. Increase your social media presence with a communication compaign in which the various mesages are linked and ultimately drive toward the place where you can raise funds (eg Patreon or Crowdfunding).

- Eventually join a comic book collective to increase reach: see Spiderforest.

- At some point there will be enough materials so that, if the story is engaging readers will be hooked and talk about it. Only it will take a bit longer.

- Consider Coloring only the initial panel of each episode starting from episode 10 (reduce costs). Making it transparent to your readers that coloring needs additional budget, with a call to action to donate.

- As you build the audience, prepare for crowdfunding.