I keep getting the spinwheel

See what is using the most memory and the most cpu by following these directions:

Checking CPU usage, energy usage, and memory usage using Activity Monitor.

Note: This will not delete any data.

You can see the running processes on your computer and also check how much memory and CPU they are using.

Launch the Activity Monitor application in any of the following ways:

Type the first few letters of its name into Spotlight. Select it from the results.

Go Finder > Applications > Utilities > Activity Monitor

Go Launchpad > Other > Activity Monitor

To view the processes sorted by memory usage, select the Memory tab. The process using the most memory will appear on top. The results are listed from most usage at the top to least usage at the bottom.

To view the processes sorted by CPU usage, select the CPU tab. The process using the most CPU will appear on top. The results are listed from most usage at the top to least usage at the bottom.

To view the processes sorted by energy usage, select the Energy tab. The process using the most energy will appear on top. The results are listed from most usage at the top to least usage at the bottom.

Report what is taking up the most cpu and the most memory.

Additionally, go to System Preferences and make sure you have the correct boot drive selected in Startup disk. You may also want to boot to your Recovery partition by holding the Command and R keys at startup, then run Disk Utility and choose the repair option.