Anyone knows what to do after building a product ?

I built a SaaS product over the past 4 months. The development part went well — but now I’m struggling with what comes next. I’ve been trying to market it on my own, but honestly, I’m failing: -SEO isn’t working -Backlinks are not coming -I’m not reaching the right audience -No clear guidance or structured approach to follow It feels like there’s a missing “playbook” after building a product. If anyone has gone through this stage or has a proven framework for acquiring users, doing marketing, or growing a SaaS from zero — I’d really appreciate your guidance.