Should I leave her?
I've been with my girlfriend for about 6 years now and in the last few months I've noticed her acting strangely. A few months ago I caught her hiding an online instant messaging conversation from me, she stated this was all innocent and was just online friends talking. A few days ago I happened to catch a notification on her phone from the same IM service she uses but the messages were definitely not innocent, it has since been confirmed that she has in fact been talking to guys online in a sexual manner and has even sent pictures of herself to people. She tells me that the reason for this behaviour is due to some serious psychological issues she's currently coping with. She is now seeking help and has promised not to do it again.
She's gone into greater depth about her mental state with me and this kind of explains what she's been doing but I'm wondering If this is just an excuse. I'm not sure if I'll be able to forget this and start trusting her again. If I hadn't have caught her I'm certain she'd still be doing it.
She wants us to be together but I just feel like I've been taken for a complete fool and I hate her for it. Any advice you guys have for me would be much appreciated.