Support for partner with BPD

Hi All,

I am pretty new to all this so any help would be great!, I've been seeing my GF for about 5 months and things have been fantastic. We are very much in love and been spending as much time as we can together. I have been finding whenever she gets completely run down she will normally spiral. She has her kid 90% of the time and only works part time when she can. The pressures of the world weigh her down. We don't live together and live roughly 45min drive apart and i'm feeling absolutely useless at not be able to be there for her. The affection stops completely, the responses to msgs that are normally constant throughout the day, get less and less to nearly nothing. I feel like i am failing her as a partner and I'm not there for her. I am after anything. Information i can read up about, strategies, do's and dont's.. I also don't want her to know how I struggle with it as she will think its all her fault. So please anything/ information would be great!