Came looking for this comment. It’s absolutely critical to know thyself, and understanding one’s attachment style is one of the easier bits of self-knowledge.
One of the most accessible books on the topic is “Attached” by Levine and Heller. For me, that book was such an eye-opener. I read it as my second marriage was imploding, and I was grabbing at everything to try to save it. The example conversations for my and my ex’s attachment styles were uncanny. I kept getting the feeling of “were y’all in the room with us for that argument?”
All relationships are transactional. There may not always be an explicit ledger with columns for AP/AR. Interpersonal relationships that repeatedly fail to provide the expected return on investment result in dysfunction and toxicity. We always pay for sex and companionship; the currency just probably isn’t money.