In love with someone you can't have because of your daughter?

Hallo, My wife died 14 years ago from cancer it detroyed me for years and it took me years to get over i have one daughter who is 16..... I was not planning to meet anyone ever because my wife was my world .I then met a beautiful woman who moved to my area for work .we became friends for a year and i realised she made me really happy and always offered advice. So i asked her for a relationship we went out for two years and she really made me feel good again .she helped in my home and if i needed a help she was always there.My daughter then last month began to play up and say mean things like shes 'a ' we dont need her etc she isnt and infact the woman i was with was shy and quiet. i really understand my daughter because she thinks no one will ever replace my wife i really do understand her and my child comes first.But this is the first woman i let into my life in 14 years and i really did like her. for my daughters sake i called the woman and asked her to meet me at the local park and i ended it with her i felt so terrible when i did it because i could see her dissapointment and saddness its been on my mind all week what i done infact i cant sleep i really never wanted to hurt her because she told me everything and i was close to asking her to marry me but i guess its over because i cant do anything until my daughter ecepts...How do i get my daughter to understand i need to find happiness? how do i say sorry to the woman i loved? Im open to any advice