You are running out of memory in your VM by the looks of it. Try increasing the VM's virtual memory.
In regard to localhost - you can use that as long as your browser is part of the same vm. You need to use the VM's network interface and IP if trying to access node-red from the host's desktop and browser.
What did you do just before it stopped working? If you changed the flow file then possibly you added something that is consuming lots of memory. If you look in the .node-red folder you should see a flows file with a .backup extension. Move the current flows file away and rename the backup to replace the one you have moved. Then restart node-red. Also you should start making backups of your files.