Breaking up and devastated

It’s been about 6 days since I broke up with my bf. We still live together and he’s supposed to be leaving at the end of the month. While I’ve been sad, anxious, going through all the emotions; he’s already staying out all night sleeping with other women. I cannot handle this pain. I haven’t slept a solid couple hours since the breakup. I went from 108 lbs to 102 in 6 days! I can’t eat. Every morning and night my heart is racing. I want to be with him so badly but I’m sticking to my guns. It hurts so badly though. Especially because he’s cried and says he wants to be with me, but he wants a relationship where he has the freedom to have sex with other girls while only loving me. Wow that killed me to hear him say. He cries because he doesn’t want me to leave his life, and I cry because I know I have to, even though every part of me wants to stay. How do I get through this? How do I let him go? And how can I just have peace? I want to sleep and eat, and come to terms with this. I just don’t know how. This man gave me a ring, met my family, loved me! But we want different things. I don’t want to feel this anymore.