the apple logo keeps popping up on my screen and disappearing

Hello rahel617,

Thanks for using Apple Support Communities! So you're having issues with your iPhone not starting up as expected; let's look into this more.

The following support article provides some troubleshooting steps to try for this behavior:

If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple Support

Specifically, take a look at the section labeled "If your device turns on but gets stuck during start up"

Hope this helps.

Best Regards.