iPhone keeps restarting on the Apple logo

Hey! I am trying to reset my iPhone 6. It was in recovery mode, and when I used ReiBoot I selected the "Exit from Recovery Mode" option. And iPhone keeps restarting and looping on the apple logo. I can't get into recovery mode. I tried all tips from youtube and from Tenorshare. Still couldn't find a solution. I am using a MacBook Pro. I tried entering Recovery mode and DFU mode, still it keeps restarting on the Apple logo. Any suggestions please?