MacBook Pro 2011 Issues - Completely Broken?

Hi there,

I'm having persistent issues with a MacBook Pro 13" from 2011.

It started a few weeks ago when during use the cursor became laggy/glitchy and the macbook would freeze up, requiring a forced restart. This seemed to worsen over a couple of weeks until it would not even boot - at which point I tried various troubleshooting actions (resetting SMC/PRAM, reformatting disk, reinstalling OS). Finally, believing the hard drive had failed, I purchased and installed a new HDD.

With the new HDD installed, I installed Sierra and for a time everything seemed to be working (this is WITHOUT restoring my files from the old HDD using time machine). However, after a few days without use, I turned on he MacBook today to find the same issues as before - it will freeze while booting at the white apple logo screen, and if it manages to boot to the login screen, it is incredibly slow and ends up freezing just as before.

The MacBook boots fine in Safe Mode - I'm currently writing this from Safe Mode in fact. I ran disk utility and it returned an error message saying 'First Aid found corruption that needs to be repaired' - I then restarted into recovery mode, and tried to verify and repair the disk, but it returns an error message just saying 'Storage system verify or repair failed'.

I'm now at my wit's end - I understand this is an old machine, but I have no idea what is going on. Is this likely to be some sort of hardware issue (perhaps logic board failure)? As stated, it is running perfectly in safe mode. I'm wondering if it's worth persevering with trying to fix this or simply replacing the machine.

Any insights or ideas would be greatly appreciated...

Thanks,

Jake