long term relationships..should I be in love?

Hey!

So I these thoughts are on my mind for quite a long time now. I have a girlfriend and we are together since 2017 august. Not that long time, but not that short either compared to the relationships in the 21st century...

My gf is really a loving girl. I know she loves me with all her heart and she wouldn't cheat on me no matter what. I would describe our relationship quality as far above average. We really understand lots of things about each other, the communication is great.

But I do not feel in love anymore. Its just not the same since a year or so. I became this really rational human being. I do really respect her and I am trying to do my best in the relationship despite that I just miss that real passion (love) behind my motives. I always think about our relationship in a pretty rational way. For example I pretty much understand that I probably won't find another girl in life with the same qualities and personality. I know that she would be a really good mother and also a really good wife. Yet.. I don't feel that real love anymore which I felt earlier. When you really lose your head and just go after your feelings..

I am 23 years old, still a bit young to plan a family and everything, but I would like to have some people's opinion who are/were in long term relationships. Will it always be like this from now?