One thing I would add to the advice above: before publishing more content, work out which of the three different problems you actually have, because the fixes do not overlap.
Open Search Console and split it this way. If most of your pages are not indexed at all, it is a discovery/internal-linking problem - more posts will not help until Google can reach and choose your existing URLs. If pages are indexed and get impressions but sit around positions 15-40, it is usually a topical-depth problem: one page per search intent, cover the sub-questions the top results answer, and link those pages to each other instead of scattering new topics. If impressions are fine but clicks are low, work on titles/snippets first - that is the cheapest traffic you will ever get.
Also judge progress by indexed pages and impressions per page cohort, not by total sessions. A year-old small site usually grows in steps once a cluster of related pages starts ranking together, and looking only at total visits hides which cluster caused the step.