I feel so sad and guilty... :(

posting as anonymous because I'm so ashamed of this :/ I don't know where to start but it all started when I had my 3rd baby who's 7 months old now... let's backtrack, I had my first at 17 years old, second at 19 and I was always confused when people would ask me if I missed them when I was away from them or if I felt this overwhelming love for them. tbh I was annoyed most of the time, I hated night feeds, i hated changing diapers, hated the screaming, the mess etc and when people would say oh but it's worth it isn't it.. I was just like hell no and would be happy when people watched them for me so I could have alone time... now fast forward to now I'm 29 and just had my 3rd baby with a new partner and I felt it... I felt that rush of love, i enjoyed night feeds because I got to wake up to my baby, I don't mind the mess or the screaming, everything is worth it.. I don't even want to let her out of my sight! which is the total opposite to when my other 2 were little. I feel so sad and guilty like I didn't love them :( I'd do anything for all of my kids! just felt differently at the start... I only started enjoying my first 2 when they could walk and talk and wasn't so dependant. why did this happen?