Need someone to help me...

I was in a year and a half relationship with this boy that I’ve fallen in love with... Well about a week and 4 days ago he had told me that he has fallen out of love with me 4 months ago and waited so long to end things because he had hoped the love he once felt for me would come back... but it ended up not coming back. He ended things right on my bed a hour after we did stuff and a week after I bought him a 364$ gift... he even knew I was getting him something that expensive for a while. But anyways he told me he still wanted to stay friends because we did promise each other that if we ever ended things we would still stay best friends just like before we started dating... but I still am deeply in love with him and I’ve been crying every day and I can’t eat or drink anything without throwing up and I can’t sleep because my mind is racing 24/7... Ive started to get lightheaded when I stand up and see black... I’ve also been reading about grieving processes and how long it’ll take to get over it... but it just hurts so much I dont know what to do most of the time and I don’t really have anyone to get advice from... I try and keep my mind busy as much as possible so I don’t think about it... but it’s just unbelievably hard when it doesn’t faze him that much that we ended things and we even have the same English class together and sit right next to each other so it’s hard at school because when I see him I think of how we used to be when we were in love... and I cant really talk to my best girl friend about this because she doesn’t date so she has no clue how I feel or anything close to how I feel... And to be honest I just need some advice of how to deal with the pain... (FYI: he was never a jerk to me. He always treated me good so I don’t hate him at all!)