relationship problems linking to mental illnesses

(i didn't know how to better title this thread because there's a lot going on, sorry!!)

so my "boyfriend" and i of 1 1/2 years have started having problems over the past month (he "broke up" with me on march 7th). i keep using quotation marks because within the past month, things have gone up and down between us. it first started out with him dropping me off at my house from school, as per usual, but instead of laughing and joking and making out as usual couples do, he broke up with me. i knew there was something going on from the very beginning when, during his beak up with me, he kept contradicting himself. (i.e. "i still love you", "i don't love you", "i don't want to break up with you"/"i still want to be with you but i can't", "i don't want to be with you", etc.) prior to any of this, our relationship has been as happy and as steady as two teenagers with depression and anxiety can make it. four days after we broke up, we got back together for two hours with positive outlooks and high hopes before he broke up with me again, saying "i don't love you that way anymore." this, obviously, hurt deeply. to make a long story slightly shorter, about a week after breaking up for the SECOND time, (this is the earliest thing i can remember, my memories between the day he broke up with me and around this time are fuzzy to me) he opened up to me and said that he's really going through a lot and that he still loves me but he just can't be with me right now, and that he wants to start over- since we did rush into our relationship- by being friends for a few months before getting back together. i agreed and said this is fine. things were going well between us, but during the course of the month, we practically acted like we were still in a relationship without calling it such. (kissing privately, hugging, saying "i love you" and "i miss you", etc.) about a week after our "starting over" discussion, i felt like he broke up with me again saying that we had to go "even slower", and i was sad but understood. after a couple days of being distant, we went back to acting like we were in a relationship again. (just to note, now that i look back on all of this, doing these romantic things with him during the past month was probably a mistake.) i've been talking to him about what's going on and we believe that he has some sort of bipolar disorder, due to his frequent mood swings, "high highs" and "low lows", and i've been constantly thinking about how he hasn't been acting like himself for the past month, due to him CONSTANTLY contradicting himself, sometimes within the same day, and he's just had this different aura about him. a couple days ago, after embracing and being romantic, he apologized and talked to me, saying "kristen, i love you, but i'm really not ready for a relationship right now. i can't do this. it's. over. i want to be with you but i can't handle it. i have to get over you. i don't want to give you false hope- well, not exactly FALSE hope, but i don't want you to get your hopes up. i've been feeling not only trapped, but pressured into getting back together with you, and that's really taking a toll on me." (that's basically all i can remember, i guess my brain subconsciously tried to block that memory from my head, with good reason.) i've been doing better, albeit him constantly hurting me, but i'm having a huge relationship crisis over all of this. i don't want what we had to crash and burn because of something that he can't currently control. please help!!!

(if anything needs to be clarified, feel free to ask)