I need the advice for the sake of my daughter....relationship advice please?

So I am 18 and he is 20. We had a baby back in August and that improved our relationship a whole lot because we matured and life was not about us anymore. But as time goes on and we get busier and busier (we both had jobs and are full-time students). it seems that we are not interested in one another anymore or maybe it is just that we do not have time. But I think he has fallen out of love with me however the more I think about it I feel more in love with him than ever before! Its a sad thing because I do not know what to do. I talked to my mom right now but she insist I only focus on my daughter and school. And I understand that but it seems like he is still apart of my life and will be forever. I think he is ready to move on but he just does not know how to tell me b.c. he knows it will hurt me. H has been there for me for the past 4 yrs and I would hate to lose him. He understands me like no one else and the same goes for me understanding him. We still see each other every Friday and all weekend b.c. that is when he has visitation with our daughter( I stay at his house b.c. I am scared to leave my daughter). But when I get there I am tired from school, work and just plan old day to day life. So I just sleep and he get upset and then we argue but ughhh I am at a crosswords as to what to do! Any help would be greatly appreciated b.c. I don't know what I would do with out him, he is a great man and would be a horrible loss in my life!