i'm a muslim, and am still in the process of becoming firm in faith. it's been difficult, and i'll be honest - there was a stage in my life where i truly believed i was bisexual, and closeted. i guess i'm not, as if i was ever interested in a girl, it was only sexual fantasies.
i'll tell you honestly - it IS a test. probably one of the hardest ones from allah. my advice to you is to remain strong in your faith, and don't let this become too much for you. however controversial this might seem - i'm sure your feelings about women will change as time passes on. i suggest reading quran and understanding more about islam - it'll really open your mind and heal you spiritually, wallahi. all i can say to you is to pray to allah to guide you, and help you restrain and control your feelings. inshallah things get better. don't feel condemned because of your feelings - there are any people in the same position as you. don't let it drive you away from islam.
i know two girls who are bisexual and muslim, and unfortunately it seems like they've both turned away from islam, feeling attacked by other muslims and what people say about homosexuality. don't let that be you. the only advice i can give you, without making it seem like i'm condemning you and forcing you to be straight, is to pray to allah. he is all forgiving and the most merciful. and remember: no one is punished for their thoughts. allah swt does not punish anyone for thinking sinful things - it's human nature to have nafs. inshallah, you will be rewarded for your struggle.