Q: Screen goes black after login, desktop won't open

my 2014 MacBook Pro was starting to glitch out and freeze a lot yesterday so I restarted it, but after that when I tried to log into my computer the screen loads for a really long time, and then the screen will turn black and the cursor becomes the rainbow loading symbol. I can move around the cursor but it won't open my desktop.

I've tried rebooting it in safe mode, which made another login screen appear after the black screen, but still the cursor turns to loading and the background freezes. I tried rebooting in recovery mode but it said that my disk was fine(?) when I used first aid so I can't repair it. I tried downloading OS X again twice but still each time it's made the initial loading slower (with the Apple on the screen) and I still get that black screen and the loading symbol. I've tried letting it just load for hours but it won't change? is there anything else I can do??