Feeling disconnected

I feel so guilty. My friend is really nice but I can tell she's in such a terrible spot. However just can't seem to bring myself to continue helping her anymore. I know she's trying her best but she is still struggling so much. Yet as much as I care for her, I just feel tired. I feel exhausted for staying up late in the night to ensure she doesn't get scared from her sleep paralysis and I try to visit her whenever she asks but I'm starting to feel exhausted. When I have bad days I have to force myself to talk to her and other people because I know she's having a rougher time but it's so painful. I can't tell her these things because I'm the only friend she trusts enough to tell me about her issues and she's afraid to see a counsellor about her problems. Sometimes when I really don't think i can talk I tell her that I'll just listen to her but then once she confides to me she wants me to give a proper reply to her situation but I just can't give it to her. She is a very sensitive person with her emotions and when I reply to her just a little bit later she becomes upset with me and it just makes me anxious when she won't talk to me anymore because I didn't respond to her fast enough. I feel suffocated with her but I know she needs help and I do want to help her and yet when I feel down i can't take a break. I feel so terrible