My boyfriend has recently turned 18. We've been together for a year, we are EXTREMELY close. We are best friends on top of our relationship. In May (about 2 months ago) I started to see a big change in him. One day he just stopped treating me the same. He used to be madly in love with me, he would tell me very often, he would always do the sweetest things for me, he would beg me if he could stay at my house longer and would never want to be without me. He loved to text me 24/7, from the moment we woke up to the moment we fell asleep. He would do all that he could for me not to break up with him, and he would beg me not to when I would suggest a break. This was not even 2 months ago. In the past month and a half he has broken up with me about 5 times. One day he just said that we were done, the longest we were broken up was a week. But neither of us did anything the other wouldn't want us to while we were 'broken up'. Every time he does this, i spend days crying, while he's perfectly fine. 2 months ago, it used to be the opposite. He knows that I'm crying and miserable, but he doesn't seem to care. People ask him why he does it and all he says is "It'll be better for her in the long run." But i'm not better without him at all. Once summer came about 2 weeks ago, we decided to be 'friends'. I'm fine with being friends, but every time we hang out as friends, he ends up kissing me first and apologizing for him being so bipolar, and that he regrets breaking up with me and he promises never to do it again. But this only lasts for 3-4 days until he starts acting strange again.For no reason he just stops talking to me, and when I ask whats wrong, he says that he thinks we made the wrong choice and then the next day we get back together. Its a cycle that's repeated itself about 3 times. About a week ago we were fine, we friends at this time, and he got mad at me for not telling him I was at one of my girl friend's house. I didn't think I was suppose to tell him since we we're 'just friends'. He got extremely mad at me for this ridiculous reason, he started cussing at me, calling me names, saying things he's never said to me before. He's never ever done any of this, and I don't get mad because I know that's not who he really is, that night after the fight that we had, he took me out to eat. I don't really know how that happened from what we just went through hours before. We sat in his car until about 3 in the morning talking, like friends. He seemed great, in one of his "up" moods, and during our talk he kissed me, I was worried about the kiss because I didn't want to cycle to continue again. He kept saying " I really hope you don't regret that." He seemed so happy that night, he spent the night, and stayed with each other til 4 the next day. We talked about our relationship, and he said that whenever he's in the moods where he breaks up with me and says mean things, he doesn't mean it, he just can't control what he says. and I believe that because I know that person isn't him. I started talking about how much he's changed and how fast it happened and I started crying. He comforted me, for the first time since he was normal, he got quiet for a while and I asked him whats wrong and he said "I just don't know how I could treat my girlfriend this way and be so stupid." He said he wasn't going to let him get into one of those moods again. and I believed him, but I was still scared that it was going to happen. When he left he did what he used to do, he hugged me for along time and told me that he loved me and left my house with a huge smile on his face.Throughout this time that he's been like this he's said that he needs alone time, which he has also never wanted, but I've been giving him as much alone time as he needs. So after he left my house that day, I knew I wasn't going to see him for about 2 days. The next day I went to hang out at a girl friend's house. We texted all day that day until I told him that we were gonna walk to get food. 5 hours later he texted me "how was your walk to the taco shop" i said "terrible, it was a long walk, why haven't you been texting me?" he said that he was mad that I walked to the taco shop, he kept accusing me of talking to people on the way there, which I didn't. I didn't think it was a big deal to walk there but i guess it was to him. He didn't talk to me til the next day, which was yesterday. He seemed okay. Last night was the anniversary of our first kiss, we had a plan to go back to where it happened. At 9 last night i was at the place and texted him "are you coming?" he said "No, sorry I just don't want to." I knew that he had switched again. I called him crying about how all of this was unfair, and he barely said a word. I asked if we could talk in person and he said no. He just seemed like he didn't care about our relationship again. Like he has been doing for this past month. And I just told him to talk to me when he's back to him old self. Then this morning he texted me, calling me names, cussing, telling me things he usually wouldn't, just like he did a couple days ago. I texted him back saying "I know this isn't the real you.. im here for you still.. I'm going to continue to put up with the name calling because I love you and I know this isn't really you.. I love you.." things like that. He hasn't responded, which I knew he wouldn't. I'm starting to notice this pattern with him, it goes from him being happy with me, to the next day where he just doesn't care, to the next day where he is completely mean to me, and then he just doesn't talk to me and then back together with me. It's really hard to deal with, but I stick with him, because I believe its just a phase, I'm really starting to question if he's bipolar. I searched up symptoms and the ones I've seen that he has is : sleep gain, loss of interest, mood swings, depression, and more. I'm not going to leave him because I know he has a problem, But is there any way I can help? What can I do to help it get better? and so he stops lashing out on me so much? Do you think it may be bipolar or something else? I wouldn't ask for help, unless I thought there was really a problem. Please help.