Is my friend a liar and how can I help her?

My room mate tells a lot of stories about her past life. I want to believe her but some of the things she says seem so extreme and there are no photos or posts on social media about any of them. This has resulted in me being unable to trust and feel sympathy even when she tells me a terrible story. I just want some outside input to see if I am being unfair or not. Here is a list of what she has said:

-Used to have an extreme drug addiction
-Grandfather is constantly in hospital and surgery.
-Has a boyfriend from back home who is a model. No pics of them together, and they are not friends on any social media. I used to ask to meet him on skype but there was always some reason why not.
-One weekend she claimed he had come to our college town and they met and had sex in a hotel. We didn’t see him at all for the whole weekend despite seeing her often.
-Was sexually assaulted on winter vacation (I hate people who doubt victims, but in combination with everything else it seems unbelievable)
-Was once declared infertile – she now gets her period.
-She also claimed she had an abortion aged 14.
-Constantly lies about having class so I don’t make her go.
-Had past very abusive boyfriend.
-Once saw a childhood friend get shot in front of her by gang members.
-Claimed her sister was on suicide watch – I have been in that situation myself and tried talking to her but she didn’t seem to know anything about what it is actually like.
-Lies to teachers about schoolwork.

I wish I could believe her but she is only 19. It seems that there is never a week when she doesn’t have some big life disaster. I have lived with her for two years and have become paranoid and unable to try and comfort her like our other friends do because I just don’t believe what she says. Do you think she is lying? How should I deal with this situation best?