I'm in love with my best friend

Hi guys, feel free to judge and please be honest. 
Back story: I am married with a 5 year old son, we have been together since I was 15... we have never had a loving caring relationship more like we live together have sex occasionally and have a family kind of life... 
I have fell in love with my female best friend. I'm usually quiet a cold person, I'm not usually emotional or cuddly or show any kind of feelings on the outside to anyone other than our little boy. But my god with her everything is perfect, I'm so happy when I am with her, she is amazing in every way, she is the only person I have 100% been myself around. It's so so strange, she treats me like a princess and she understands my situation. I don't know what I'm to do. I don't think I've ever felt like this about anyone! 
My husband hasn't done anything wrong. I just didn't know that I had this side to me, I can be loving towards him and he will just tell me go away, we don't spend time together, we have nothing in common and we are completely different, we have never been like lovey dovey I just thought that was who I was but apparently not. He hasn't done anything wrong I don't know what to do I feel so so bad. I cry every day because of how I feel but I know I've brought it on myself. I didn't mean for this to happy. But what do I do? Could I be a lesbian mum? I have no idea what to do! 
I just know I really am in love with her..