unable to access account

[abirt]

I’m a newbie, so my apologies for the non-tech description:
I’m on Mac OS X 10.9.5
I’ve updated to 8.0. When I enter my password, the wallet takes ages (hours) to open (if it does at all). The entire time my computer seems to be putting a lot of effort into it. I’ve tried restart multiple times - this does not seem to affect the problem.

A couple times (after 2 hours or so), the wallet did open, but  listed ‘no connection’ and was not able to sync blocks.

I tried 'Accounts -> Go to My Accounts'; I entered my password, but nothing shows up in my wallet (it’s empty of all data and my own account details. Text reads: 'There are no transactions!').

I imported from my backup .json and now I see an entirely blank screen in the application.
Am I doing something wrong?
What should I try next?

Thanks in advance for your help!