Heartbroken, betrayed & I can't stop crying

Talia • 20 years old
I'm 17, I've known my best friend for 2 years & we had this seriously amazing connection. Whenever I needed advice, he would write me paragraph after paragraph of amazing advice. He was there for me through thick & thin. I've loved him since I met him. Then a couple months ago, he tells me that he's felt the same way for me since he met me. Everything was perfect. But he has a bipolar disorder & tried breaking up w me 3 times out of 2 months. He practically begged me to be with him. I dropped my ex & everything for this guy. He's come over met my parents, bought me all of these gifts. 1 moment he's telling me that he thinks I'm the one, we made plans for after high school & everything. Then on Jan 17, he's telling me he wants to slow it down b/c he's not ready to pursue anything with me b/c he's still hurt over his ex. Then the next he's telling me that all he wanted was to be as close as we were before when we had fallen off at one point & he thought the only way to get back that closeness was to be in a relationship with me. I just feel SO heartbroken , betrayed & empty. Not only did I lose my bestfriend & lover but the one person that I trusted with EVERYTHING completely f***ed me over like this. I can't stop crying. I cry everyday & I'll never be the same for it. & it's not like I can avoid him b/c I have class with him every other day. Can someone plz help me thru this, I can feel that I'm starting to lose myself over this pain. I can't take it.