My daughter isn't comfortable around me and my fiancée

My daughter is 4 turning 5 in a few months. Her mother was angry at me for a long time because I wouldn't commit to her. She denied me of seeing my daughter and told me the only way I would be able to see her was if I would agree to marry her. I decided to just leave it alone and move on with my life which I regret 100%. I'd do anything to be there for my daughter's growing up. Since then I've gotten engaged and in contact with my daughter's mother through mutual friends. I first got in contact with them last year. I video-chatted her, talked to her on the phone, visited her, all of that. I wanted her to become familiar with me and comfortable enough to want to start staying over to my home sometimes. She's been over to my home with her mother a few times. When her mother left is when a problem pursued. She would completely break down and refused to allow me or my fiancee to touch her but she stopped that now. When we brought her last month to stay the week with me, she was hesitant to do or go anywhere. She was happy and excited to be talking to me on the phone and video call but she was acting super shy and scared when she saw me in person.I still get her on the weekends. When we try to play with her or take her somewhere, she doesn't say anything. She just mumbles things and looks miserable or afraid to the point of crying. I'm trying to get her to start calling me "Papa" or "daddy" but she just doesn't say anything to me. At all.I just want a good relationship with her. I don't want her to think that I don't care about her or don't want to make an effort because I'm sure she's confused as to who this man who just popped up out of nowhere and keeps taking her from her mother is.Sorry if this is all over the place. I'm not good at typing my thoughts out via /r/Parenting http://ift.tt/2pm6VX1