PLEASE HELP!?! CAT MISSING!!!?

So I slept over my grandmas, and i told my brother to take my cat inside at 8:00. HE PURPOSELY DIDN'T DO THAT AND LEFT MY POOR CAT MAX OUTSIDE! It started to rain and lightning and thunder, so he ran away somewhere, and i CANT FIND HIM!! I've been crying myself to sleep the past 2 days. He is only like 3.5 months old, and i worry that something will or has killed him. Also what if he starves! WHAT IF HE WONT COME BACK???? will he ever return? Please help me, i miss him soooooo much. :( :( :( ITS BEEN 6 DAYS SINCE HE RAN AWAY!