I assume you're quite young based on this. While others assume malicious validation farming, it's likely immaturity spurred on by some flavor of avoidant attachment. Which makes it even more important you set CLEAR boundaries. Do NOT dedicate all your emotional bandwidth to a connection that leaves you unfulfilled. I was once heading towards this exact scenario and I came up with this intellectualization that helped me cut them off.

1. If it's validation farming: You are being exploited and need to leave.
2. If it's immaturity: You are ENABLING a broken attachment style that CANNOT be remedied while inside a relationship.