Need more information - what version of Ubuntu, had you done anything other than an update/upgrade? Did you check which packages were upgrading? Is there an actual error showing?
Can you get to a TTY with ctl alt f2?
Yes that works but I don't think my network card is enabled yet.A text console. Pressing CRTL+ALT+F2 should get you a basic text screen with a log in prompt. If you do get one, can you log in there?