Can't get in to Titan to continue my main quest.

Every time I get stuck on an eternal loading screen, but I can talk to people in my party who are in there. Then I have to restart the whole stupid thing and it won't let me back on for at least a half hour. Getting reaaaallllyy annoyed, haven't ben able to get in since patch and I want to continue my main quest.

Fix please?

Suggestions?