Car stalls and not from dropping clutch.

[CA18_S13]

Well for sure i know its not the starter. Earlier this morning i was gonna take it to the shop to get the alternator checked out when on the way there i was in third coasting at around 45 and the rpms drop to zero so i get into a left turn lane to clutch in and start it again. It cranks and cranks and it feels like the battery is loosing power. Well lucky for me my dad is in the back of me in his car he jumps out and helps me push it into this side street by a church and community. I didn't let off the clutch when i was at 45 and i didn't stall out. I hope it isn't a really bad electrical issue.