My notebook Lenovo G780 lags. I use Linux Mint

I use Linux Mint 18.2 Sonya \n \l

Here is my journalctl -b -p err:

-- Logs begin at Thu 2017-10-05 17:07:22 MSK, end at Thu 2017-10-05 20:47:24 MSK
Oct 05 17:07:22 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }
Oct 05 17:07:24 ivan-Lenovo-G780 kernel: ata3: exception Emask 0x10 SAct 0x0 SEr
Oct 05 17:07:24 ivan-Lenovo-G780 kernel: ata3: irq_stat 0x00000040, connection s
Oct 05 17:07:24 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }
Oct 05 17:07:26 ivan-Lenovo-G780 kernel: ata3: exception Emask 0x10 SAct 0x0 SEr
Oct 05 17:07:26 ivan-Lenovo-G780 kernel: ata3: irq_stat 0x00000040, connection s
Oct 05 17:07:26 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }
Oct 05 17:07:29 ivan-Lenovo-G780 kernel: ata3: exception Emask 0x10 SAct 0x0 SEr
Oct 05 17:07:29 ivan-Lenovo-G780 kernel: ata3: irq_stat 0x00000040, connection s
Oct 05 17:07:29 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }
Oct 05 17:07:31 ivan-Lenovo-G780 kernel: ata3: exception Emask 0x10 SAct 0x0 SEr
Oct 05 17:07:31 ivan-Lenovo-G780 kernel: ata3: irq_stat 0x00000040, connection s
Oct 05 17:07:31 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }
Oct 05 17:07:33 ivan-Lenovo-G780 kernel: ata3: exception Emask 0x10 SAct 0x0 SEr
Oct 05 17:07:33 ivan-Lenovo-G780 kernel: ata3: irq_stat 0x00000040, connection s
Oct 05 17:07:33 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }
Oct 05 17:07:35 ivan-Lenovo-G780 kernel: ata3: exception Emask 0x10 SAct 0x0 SEr
Oct 05 17:07:35 ivan-Lenovo-G780 kernel: ata3: irq_stat 0x00000040, connection s
Oct 05 17:07:35 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }
Oct 05 17:07:37 ivan-Lenovo-G780 kernel: ata3: exception Emask 0x10 SAct 0x0 SEr
Oct 05 17:07:37 ivan-Lenovo-G780 kernel: ata3: irq_stat 0x00000040, connection s
Oct 05 17:07:37 ivan-Lenovo-G780 kernel: ata3: SError: { CommWake DevExch }

what's the problem? I am a just a user, I never dug into something deeper than simply installing different programs and using git, sql through bash, so to me the output has no sense( I don't even know does this output have anything to do with my notebook lagging, I just read about this command, journalctl - b -p err on some Russian Linux forum )

Either your harddisk is dying or there is a loose contact somewhere on the way from SATA controller to disk. The disk is seen by the OS as unplugging and replugging every few seconds.

THis is serious, have someone with experience try to recover you files if you don't have up-to-date backups.