Low Milk Supply Crisis 😩😢😭

My little girl is 9 weeks on Wednesday and is breast fed. She’s started cluster feeding ever 45 minutes to and an hour. She use to be good at sleep now she just acts hungry all the time. She’s been cluster feeding for the past 4 days and seems to drain me each time and still wants food but nothing seems to be coming out. I even had to give her formula to get her to go sleep as she kept coming off when she realised nothing was coming out. I’m trying to express when she’s asleep so I can try and increase my milk but nothing seems to work.

Any ideas on what to do or if there is anything I can take? I really don’t want to put her on formula full time. I prefer feeding her by breast.