Michelle, it sounds from your post that you are a genuine, caring, loving person and have a lot to offer...But...
"he throws things in my face when he get's into his moods"
this is not ok. This is not an acceptable way to be treated by anyone. You don't deserve to be treated like that. Untreated bipolar disorder is not an excuse for abuse and violence. It is your responsibility to keep yourself safe from this kind of mental and physical violence.
"i don't know if I can help him"
no. You can't help him. Medication can help him. Professional psychotherapy can help him. You can love him. You can support him. You can enjoy the person he is - but it is not your role to help him. Don't cast yourself in that role. You're not his protector, nurse or mother.
"i'm starting to feel like i'm going crazy"
it is time for you to start helping yourself. You need to look after yourself. You need to consider what you want for yourself. It is ok to walk away.
I really, honestly and truly wish you the very best. Good luck.