Hi, welcome to justanswer.com! My name is Mike.I am going over your question and I will be with you shortly.
Hold the power button for 10 seconds then restart and hold the Shift key until you see the Apple logo. This will activate Safe boot and it will check the drive for errors among other things. It may take longer to boot and you may see a progress bar during part of the process. If it starts up OK login then restart the normal way from the Apple Menu. Hold Shift when opening Safari, then quit Safari and open Safari the normal way. Let me know after.
Did you try that?