Battery died 1 wk after installing Sonoma thru OCLP. What do?

I bought a 2016 MAcbook pro with macOS Monterey installed. Monterey expired last month which means Microsoft word doesn’t work anymore unless I upgrade. . So, I installed MacOS Sonoma through OCLP. 1 day after installment, My MacBook cant survive without being continuously plugged in. 3 days after, my MacBook cant charge past 3%. 1 week after, My MacBook battery died. It cant charge anymore. What should I do.