Me and my best friend

hello, I know there is a lot of questions like this asked. I have a best friend who I have known since I was 2, I am now 18. we grew up together and became very close, my mum and her mum are also best friends which always made it a lot easier growing up. I started having feelings for her when I was about 12, everything she did I was always amazing by it as she is amazingly talented. when I would go round we always slept in the same bed with each other (nothing sexual) we just used to cuddle up and stroke each others backs as it always made us feel good and we would sometimes write messages on each others backs using our fingers, we are just such close friends. I remember her and her mother saying that we will get married when we are older which I guess stuck in my head as I think I would be happy with only her. I am a very pessimistic person but she would make me feel like I meant something. we have so many songs that we said where our songs and most things remind me of her, I never go less then 2 hours a day thinking about her. she and her parents moved to Ireland (which isn’t that far I know) and her brother who I am also good friends with stayed here. she came back for about 6months and got a boyfriend which didn’t make me to jealous as I didn’t expect her to not have any relationships while she is growing up as I know she does and acts in front of me in a way she wouldn’t with anyone else. her mum was round mine one evening after falling out with my mum for about a year so I was quite happy that they are friends again but then her mum told me that she is pregnant, my heart just shattered as I love this girl so much, she is the only thing I would want to live for and I know it sounds silly and typical but she has helped me through 2 big life events and I don’t know how to cope without her. she had her baby and he is beautiful, and I wouldn’t wish noting bad to happen to her and her boyfriend but I just don’t know what to do, as I don’t want to ruin their relationship but I don’t want to have one with anyone else. I don’t really like talking to people I know about these issues being a male and all so I am hoping I can get some advice/help on here, if you haven’t fallen asleep whilst reading of course. thanks to whoever takes time to read.