Salam, I'm a bisexual Muslim girl and this entirely my sole view, opinion, and way of thinking.The Qur'an forbids I associate my justification for this 'sin' with the Qur'an itself, but I will be explaining and making references. I'm also no scholar of any sort, I'm just a regular teen that has gone through the basics everyone else has. My mother is a convert and my father is more traditional. With this is mind please continue:
The main reason bisexuality or homosexuality is considered haram is primarily because of the disagreement it causes within families, the detrimental affect it can have on your life if you cannot find acceptance from those around you (i.e. drop out of college, waste your days away only indulging in yourself, etc.), and diseases that can be caught through this practice. I however still do not see disease as a full reason since it can also be contracted through interaction with the opposite gender. Allah (swt)'s words are the most wise and are in our best interest, I agree with this. However, they are also a form of guidance. Guidance should be followed in the best way possible, but since I also believe God the most understanding, and unbiased, if you have good reason for committing homosexuality, it will likely be forgiven. But, also, you cannot let simple excuses get in the way of your worship. You may not allow your homo/bisexuality get in the way of your worship and everyday life. I know many people out there believe religion is bs, but I still have faith and love the first-world blessings I have received and am happy to say it might've been the only thing to move me on from depression and PTSD, despite the inherited blurbs out there, I chose this religion and it was not chosen for me. I also want to remind you that your fear is good and is out of not wanting to disappoint your creator, however, remember that God is Ar-Rahman (All Loving as a pregnant mother loves her fetus) Please, brother, do not indulge in only physical pleasure and remember your spirituality. Bless. (Assalamualakum)