Q: screen wont go past the progress indicator screen

Hey emmy7786,

I understand that you are having some issue starting up and running slow. Let's see if we can get tot he bottom of the issue. 

I would start with verify your hard drive by using Disk Utility for any possible errors that could be in relation to your issue. You can get there by booting your mac to OS X Recovery or Internet Recovery. Keep in mind that if you have issues booting to either option, you can use Single User Mode to use the "fsck" commands to do the exact same thing. Take a look at the article below to walk you through how to do these steps to help figure out what is going on. 

Resolve startup issues and perform disk maintenance with Disk Utility and fsck
https://support.apple.com/en-us/HT203176

Let me know what you find out after the test completes.

Take care