Start your Mac in Safe Mode. Safe Mode or "Safe Boot" is a troubleshooting mode that bypasses all third party system extensions and loads only required system components. Read about it: Starting up in Safe Mode
Safe Mode is a troubleshooting mode only. Startup will take a long time and some features do not work in Safe Mode, but if it eventually boots and runs programs then you have a non-Apple system modification that is preventing your MBP from starting normally.
If it does not boot in Safe Mode then repair your startup volume using Disk Utility again. If it reports errors again the reason may be third party software causing it to be corrupted, or it is mechanically failing and needs to be replaced. In the latter case back up your data and replace the disk drive with a new one.
Reinstalling OS X generally does not fix problems such as this.