Engaged but having problems

Maybe you can help with this. I am real love with Fiance and would do anything for her and love her to bits. However it is like I keep on doing something wrong and then she will keep referring back to it is deep conversations on how bad I am and not caring. Really I am looking for some honest advice, If I have a problem then what can I do to sort it. A few examples: I used to talk about my neice who is a 5/6 yr old young girl and joke around saying she was my younger girl friend, obviously nothing sexual but just she is young and cute and we used to be close when she was first born. However my fiance was saying that she has never referred to anyone else as her boyfriend and it was making our relationship of less importance. Another example is that I used to be closer to my mother. My fiance has not travelled much and on her first flight to see me she had wanted me to fly all the way there and then fly back with her. However both myself and my mother thought it was a bit excessive, however this was my choice and NOT my mothers but we did chat about it. I personally thought that it would be better to use the flight cost so I could visit another time. However this was seen as putting my mothers thoughts above hers and not being there for her. This is something which is brought up MANY times now. Also the first time she came to visit, we had flown back through 6 time zones and was the first proper international flight she had been on. As I run my own business I planned to work the first day back which was in my home and allow her time to sleep and rest and catch up after a long flight but this was seen as not being there and caring for her. As mentioned earlier that I run my own business which is soon to be over 3 yrs old. Anyone who starts a business will know that 80% fail in the first 3 yrs and the rest you have to do everything to make it work. However we have had conversations where she says the business is more important than her. In the last year I have travelled from UK to USA 6 times to visit, would like to do more but that is hard. It seems that most conversations come back to that she does not think she or our relationship is the most important thing to me, whether it is my neice, mother, business or whatever is more important than her. I am looking for some help on this as it always appears that I am wrong. I am happy and willing to be shown wrong I have made many mistakes which I am not proud about but I do want this relationship to work.