I Cannot Log Back Into My WhatsApp Account on My Original Phone

On 02/06/2025, I accessed WhatsApp using a different phone, resulting in my account being logged out from my personal device. Since that time, I have been unable to access my account on my original device. It keeps displaying a message that says, “Download the official WhatsApp app to log in.” I’ve downloaded the official version several times, even attempted the APK version and followed every possible step I could think of, but nothing has worked. I'm really dependent on WhatsApp for my everyday communication, and this problem has significantly affected my ability to connect with others. It’s quite disappointing to find it difficult to access reliable technical support. I would greatly appreciate any assistance in resolving this issue, as my options are dwindling and the stress is increasing daily.