Givers and Takers - letting off steam

Today my cousin, whose husband has been suffering with ALS for years called. She was, once again looking for a shoulder and I was it. I listened to her, grievances, concerns, crying etc. for several hours. Oh he was diagnosed with cancer now and can't have any treatments because of the other thing. What is she going to do without him? For years she has claimed to be looking for a ranch home because the stairs are a killer for her H. to deal with but never seems to find one. I once, during one of these conversations mentioned I was having difficulty finding someone to help with housework and right away, once it wasn't about her she had to go.

After the call ended It occurred to me that she never asked how I was, never asked about my H and how he was doing....nothing. She has no idea how my husband has deteriorated, how I have deteriorated and the things I have posted here because if it isn't about her and her plight she has no time.

Point being, I am teed off about this.

Question - I feel used and would it be terrible if I just stopped talking to her when she calls? I get 2-3 calls a month from her like this.
Yes, her husband is in bad shape, and it is tough, but I am floundering through a lot of the same problems.
I have given her support and suggestions, but I realize now that she has never done any such thing for me. A total taker...and I am a tired giver.