What should i do if my daughter looks nothing like myself or her mom?

I have 2 daughters my first daughter is 2 years old (weighing 24lbs) and you could put my baby picture next to her and its an identical match brown hair, brown eyes the only difference is she is a girl of course and she has the most beautiful curly locks and my hair was wavy but other than that she's basically me as a girls. What first started my doubts was before my "second" daughter was born was the fact that we weren't intimate nearly as much as we were prior to my first daughter due to small bickering, it still happened but not as much. When first daughter was born I stayed in the hospital for 7 days without hesitation and when I held her it like there wasn't anything in this except me and her, that's really the only way to discribe it. I felt so connected and knew everything in my life was perfect. Then when my second daughter was born (although I felt very sceptical) I was there at the hospital when she was born. I was excited never the less and put the sceptisism to the side and when I finally held her I didn't have the same connection it just felt wrong, the very next day I went back to work (that's how strongly I felt about it) and I carried that guilt with for a long time. As I said before my first daughter is 2 years old, brown hair, brown eyes and weighs 24lbs and there is no denying she looks just like me. Now my second daughter is 1year and eight days younger and weighs 22lbs stands just as tall as my first daughter with blonde hair and blue eyes. Also my fiance is brown hair brown eyes as well. I've asked everyone I know to tell me who my second daughter looks like and nobody has said that she looks like me or her (my fiance), And what finally sent me over the top was two days ago my fiances mom said and I quote. "Are you sure this baby is y'alls". Now knowing that her mom knows good and well she came out of my fiance, to me what she really meant to say is " are you sure this baby is mine". For 13 months I've treated her as if she was my own, never putting one in front of the other and just being as good of a father I can be. At first it was hard to be around her (my second daughter) because I didn't feel the same, no matter how hard I tried I didn't have the same instinctive feeling as I did and still do with my first daughter. Now I don't know what to do.I have never neglected her and over time grew closer to her until my fiances mom made that comment and now all I can think about is all the overwellming feeling that she is not my daughter. No one on either side of the family has blonde hair or blue eyes and as she gets older she still looks like either one of us. I have a feeling of what needs to be done but I wanted some un bias opinons. I hope this is read by someone that have some helpful advise. Thank you in advance for taking the time to possibly help me with my undeniable delima.