As I read your update of the situation I was going to say exactly what LOCKDOWN is suggesting.
She is starting to dump on you a lot. Which is fine to a degree because you do have to have some compassion for building comfort. But at the same time you should start acting disinterested when it becomes too often ( which you should honestly feel)....you dont want to be associated with all this drama in her head, you want to be the fun guy
When her complaints and concerns are becoming too negative and repetitive just cut her off and say " You know this is getting heavy. And I have some BS stuff going on too. So much Stress!.... I need to get my mind off this stuff and wanna have some fun. Lets go to _______ and get our minds off all our crap and have a fun day."
Since she voiced that she is concerned about getting into another relationship...go with that. Keep it casual and say all you want to do is have fun and do cool shit with her because you enjoy her company. If she throws one of those emotional LMR things just say "Whoa. Settle down little lady. Who said anything about clingy emotions? Life is too short and I dont even know you that well enough to give up my valuable cache of emotions to someone who is not even my gf."