Lightroom will no longer open on Mac

Hello!

I have used lightroom for a few months on a macbook pro. I haven't used it in abut 2 weeks, since I did not have any sessions to edit. However, for the last few days I have tried to get it to open, and it won't. I click on the app, the initial screen comes up, and then it freezes my entire computer. I've tried to update it, but there are no updates to install. I have cleared the memory on my computer by transferring all images to an external drive, and it still won't open. Any suggestions?? I have 3 sessions needing to be edited so I am in quite a jam if this doesn't work! Thanks!