It's All in My Head

hello, I hope that by writing here I'll get help or advice on how to help my girlfriend whose struggling with mental issues. She has been struggling with mental issues even before we were together, it was way worse before because she used to do self harm and just often isolates herself. She's several months clean of self harm now and likes going out with me or spend time together. Yet, she still have this depressive episodes and I think this thing called brain fogging. She told me that there's too many things going on in her mind always and sometimes when it gets worse she would not eat for days and gets very emotional about things that she often overthinks and she told me that she just feels very heavy but she does not know why this things trigger. I know Profesional help is needed in these cases but it costs too much here in our country and we're still students, I hope I can get some advice her and learn how to deal and help my girl.