So sorry you are dealing with this. I have bipolar disorder type 1 and I can tell you, @Skeezyks is spot-on. If your BF is not going to take his meds, see his psychiatrist and/or therapist, and either ask for or be open to help, well, then, there is really nothing you can do. All the love in the world isn't going to stabilize his bipolar disorder. This is a lesson many people with this illness must learn at some point. That's one. Two is, I don't think you should put much stock in what he is telling you about how he feels about you. He is probably having a very difficult time processing information and is likely not thinking clearly--at all. He sounds confused because he is confused. His brain has been hijacked. It's very difficult for him right now.

The good news is there are medications out there that can really help people like your BF. The question to me is whether he is in a place to receive that kind of help. I hope so. Sending you positive vibes and prayers.