Hi @JaneBee,
I understand the feeling you described but in a different way. I go through periods where I feel like I'm am only there because they felt like they had to invite me.
But I don't fit into the group because I don't share the same interests that they have. I often felt like that so I stopped agreeing to go then they eventually stopped asking.
But recently I met up with a person who use to invite me out with their other friends and our discussion came around to my not joining and she said that they had tried to bring me more into the group but kept pushing their efforts away.
As for attracting toxic people I get that too, but it is hard when you don't know what they are like till they are using you.
I have found myself thinking that I was using people too but after talking to a few them and trying to apologise they told me that it wasn't that way at all. I had helped them and been there when times were tough now they are returning the favour.
It may not be the same thing but maybe sit down and think about it clearly is it using when you need support and would support them in the same if they needed it.
Maybe talk to those you feel you are taking advantage of, do they feel the same way.
I may be wrong but to me it sounds like what you want from these interactions is the interaction, feeling like you are not alone and that you have support.