Girl I’ve been going out with is no longer answering my texts.

I’m (24 M) no casanova, but I’ve had my fair share of hookups throughout uni, and from my experience, it is fairly common to stop texting casual ones every now and then when interest dies down. Relationships wise, I’ve only had one serious relationship that lasted over a year, and only once have I tried something serious with a girl I initially only planned to hookup with (which only lasted for about 3 months).

Now, there’s this girl (22 F) I was friends with initially (about 2 years or so), who I kinda developed a crush on but never did anything since she had a bf at the time. About a month ago she kissed me and I returned it; turns out she broke up with her bf in august, and we started hanging out with plans to see where this would go (we spoke about what we wanted). Everything was going fine, we texted everyday and flirted, but suddenly about 5 days ago she stopped texting back and has yet to even read my texts or DMs (she is still active on social media).

I know I might be a hypocrite since I have also stopped texting someone in the past without explanation, but not on a girl I was serious about, and I don’t have an idea on how to talk to her and ask her if something’s wrong without coming off as too intense or insistent (taking into account the lack of experience relationship wise).

Does anyone know how to approach this situation? Should I wait a few more days or text her right away? Should I try to ask our mutual friends before trying to talk to her?

TLDR: Girl I’m serious on stopped reading and answering my texts after a month of going out; got almost no experience relationship wise aside from hookups, and don’t know how to talk to her without coming off as too intense.