Go announce your startup publicly, call yourself a founder, talk about your startup, because it turns out becoming a real "startup" is mostly about belief rather than merit.
When you do something as bold as launching a startup there is a lengthy period of time where you feel like you're telling a fictional story. In fact you are, and I would argue that's ok, because oddly enough some things become real not because they've met some objective measure of merit, but simply because enough people believe it.
In the Yuval Noah Harari's book Nexus he writes about Objective, Subjective, and Intersubjective Realities and makes a really interesting point, we all intuitively understand objective (measurable) and subjective (opinion) realities but most of our daily experience is intersubjective reality: something that is real just because people say it is (e.g. currencies, governments, borders).
Launching a startup is no different, you have to talk about your startup as if it's real, even when it feels like you're making up a story. Eventually enough people will believe it's real and that is an important early step towards future success.
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