Sadly, that "friend" does sound like a 'user' from your description. Stay away from those types; negative and emotionally draining, in addition to the financial drain.
I observed from my MIL's situation that the lack of socialization was one of the most serious problems she faced in aging. She found it difficult to make friends on her own.
In contrast, a couple of the same age as MIL were good friends of ours. They had many hobbies and were very social. I mentioned my MIL's problems of her friends aging and dying off. Only half-jokingly, my friend said, "Yes, we had that problem too. We solved it by making younger friends!"
That is in fact what they did. They were open to the possibilities around them, and made friends of different ages.
Interestingly, an elderly neighbor of ours had a similar attitude. Right up until she passed away, she loved meeting new people and making friends.
I keep these two people as an example to myself. We don't have many friends, but we do have a lot of interests and they keep us busy. But I think about how I would have to change my life to include more people, if my DH wasn't around.
It's very difficult to face, and I hope you are able to find some new friends.