anyone else ended up in this type of relationship

where the person makes you feel like they really need you and at first it feels great and feels like authentic love but then you realize they really dont care about your wellbeing, they just want to be loved and want what you bring in their lives. but that feeling of being needed makes us feel loved. i swear my ex just has to cry and there i am throwing myself in front of a truck for her (figuratively speaking). she makes me feel like she is so lost without me and she needs me so much but she only cares about herself.