I feel like this girl I've been dating for 1 month as of today is cheating on me. She is always talking about this guy named Austin that she is "just friends with". When I go to call her it always sayes she is on call with someone else and then she sayes its Austin and she will call me back in a bit. When I do get on call with her she asks for all my attention, so I give her all of my attention, but I just feel like she isn't giving all of her attention to just me I feel like alot of it is going to Austin. I just need help figuring out what I should do

Edit: ive asked her before if she is cheating on me and she got angry and Sayed "WERE JUST FRIENDS IF YOU DONT WANT ME TO HAVE GUY FRIENDS THEN LEAVE" but I don't care if she has guy friends but he doesn't feel like a guy friend. Also another thing is that she was the one to ask me out idk if that has any relevance.

Edit 2: she is very suicidal and could end up relapsing and start cutting again

Edit 3: I talked it over with her and there is more then meets the eye. So apparently Austin was trying to attempt suicide and she was only trying to help him say alive. She sayed they weren't dateing or anything like that, she showed me screenshots of the convo and I felt so bad. I went over to her house today and everything in-between us is normal again. Thank you everyone for your help.