I think Mojave corrupted my computer...

Try to boot into Safe Mode, Mac OS X: Starting up in Safe Mode. If you're able to do that then reboot normally and see if there's any changes.

Otherwise boot into the Recovery volume (boot with the Command + R keys held down), select Disk Utility and run First Aid on your boot drive.

Additionally, download and run Etrecheck. Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

And, as recharges said instigate a back strategy ASAP. The easiest is to get an external HD that's about 2-3 times the size of your MBPs drive and use Time Machine every time you're in your room and working on the MBP.

being a student, you learning.

-- 1 -- One of the things to learn, is to have multiple backups of your work.

-- 2 -- resist the impulse to be the first on the block with the new shinny thing. This is true for your "must" work production machine. Get an external drive. Install there. See how it goes.

You top priority is to get a backup of your files. You should have your critical files backed up in several places. Get a free dropbox account. Bundle all you critical files in a zip archive. upload to dropbox. Do not install the dropbox app on your machine. dropbox app a a syncing server. delete a file anywhere and it's delete everywhere. if you only have dropbox files on the server, you will know what delete does. Write all passwords on a piece of paper and keep in a safe place.

try:

Try a safe boot. You may be having a problem with the gpu. safe boot doesn't use the gpu.

Shutdown your machine. Hold down the shift key. Poweron. The boot up will take longer than normal because the filesystem on the startup drive is being checked and repaired as needed. All about safe mode including what features and apps safe boot leaves out.

http://support.apple.com/kb/ht1455

http://osxdaily.com/2017/02/23/where-photos-files-located-mac/

This is controversial around these parts, but I recommend you get your photos out of the Apple ecosystem and store them as one photo per file on multiple external storage devices. For long term storage, don't rely on usb memory sticks nor external ssd drives. LoC does not have data on the reliability of usb memory sticks. Apple seems to be saying do not store photos on external ssd drives. One device should be off site. Using a cloud service is fine. Remember a lot of cloud services are sync services. That is should the file be deleted on the local device, the photo will be deleted in the cloud. For this reason, I never install the cloud service software on my computer. I use only file upload. For those who complain, my assessment is that the apple Eco-system doesn't match Library of Congress's requirements for digital archiving.

informative video:
http://www.digitalpreservation.gov/multimedia/videos/personalarchiving-photos.ht ml

printed version
http://www.digitalpreservation.gov/personalarchiving/photos.html

General information on digital preservation:

http://www.digitalpreservation.gov/personalarchiving/

If you have the money, see professional help. drivesavers.com

Perhaps Disk Warrior will be of some help:

http://www.alsoft.com/DiskWarrior/

"Stellar Phoenix Macintosh - Mac data recovery software, recovers data from damaged, deleted, or corrupted volumes and even from initialized disks."

They have a trial version, so I guess you can see if your data can be recovered...

http://www.stellarinfo.com/mac-data-recovery.htm

"Data Rescue II is the best data recovery software on the market for recovering files from a problem hard drive. Data Rescue II works when other tools fail. Data Rescue II is also completely safe to use since it does not attempt any risky repairs to the drive while its scanning."

http://www.prosofteng.com/products/data_rescue.php

FileSalvage is an extremely powerful Macintosh application for exploring and recovering deleted files from a drive or volume. FileSalvage is designed to restore files that have:

-- been accidentally deleted.

-- become unreadable due to media faults.

-- been stored on a drive before it was re-initialized/formatted.

http://subrosasoft.com/OSXSoftware/index.php?main_page=product_info&products_id= 1

"TestDisk is a free data recovery utility. It was primarily designed to help recover lost data storage partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally erasing a partition table)."

http://en.wikipedia.org/wiki/TestDisk

Wondershare Data Recovery for Mac

"Recover lost photos, video, documents, email and archive files from any Mac-based hard drive or external hard drive, iPod, USB drive, SD card, digital camera, mobile phone, and MP3/MP4 player, due to accidental deleting, formatting, virus infection, improper operation, unexpected power failure, and other unknown reasons. Also, iPhone recovery allows you to recover lost photos, videos, SMS, contacts, note, calendar and call history from iTunes backup file. With the free trial, you can preview all your recovered images, videos, music, documents and archive files prior purchasing this Mac Data Recovery."

http://software.bigbigsoft.com/data-recovery-mac

"If there is any chance of recovery at all your best bet is Prosoft Data Recovery." by macjack
https://www.prosofteng.com/datarescue-mac-data-recovery/

Eric Root's list:

https://discussions.apple.com/thread/7574735?answerId=30259740022#30259740022

Chterando's list:

https://discussions.apple.com/thread/7133319?answerId=31780403022#31780403022

I tried to restore my MBP that was behaving out of ordinary but ended up with two of may time Machine disks being corrupted to the extent that I could see the folders and file disappearing in front of my eyes. I no longer can mount these disk (WD & Lacie) I am very annoyed loosing months of work

I have the exact same problem with two 13" mid-2012 MBPs that I manage. Both have been upgraded to 16GB RAM, and 500GB Samsung SSDs. Resume after hibernate results in some kind of memory corruption that manifests as multicolored "static" on the screen. Some UI elements appear to be uncorrupted, e.g., the password box.

I've been searching the internet for the past few weeks to see if anyone else has had this problem, and this is the first post that I've found. Before I roll back to High Sierra (which worked just fine), I'm going to try resetting NVRAM first to see if that helps. Then I'll try running the disk integrity checker in recovery mode. Not sure where else to go after that.

Did you manage to figure this out at all?

I think the encryption in Mojave corrupts the disk. It has damaged two external disks of mine and a flash drive. You might be Ok if you don’t encrypt your drive