Q: My iPhone 5 is driving me crazy :'(

Hi,

My iPhone 5 all of sudden decided to power off. I tried to reset it but it wouldn't  the screen was totally black! I plugged it into an adapter and it showed low battery symbol, I left it for a whole night to charge but when I checked in the next morning it was still low battery. I connected it to my mac but it wasn't recognized by iTunes, I tried to get it to recovery mode and it successfully did, but still I couldn't restore it and low battery showing plus apple logo comes on from time to time with error 2001. I took it to someone and he fixed it for me. But now it happened again, and I couldn't fix it like the guy did and I can't go back to him and ask him to fix it again. iTunes symbol is now showing but it isn't restoring and error 2001 appears.