How did you go from "I built my own" to making your first few sales?
Then I started sharing the progress on LinkedIn/X, my co-workers shared on their network too which also helped.
After 4 months I put a price on it and sold it with a 50% discount for early adopters. A lot of people bought it, which to me was a signal that I was into something that could become bigger if I invested more time on it.