As someone with a lot of anxiety around conflict, I get coming onto anon and venting. It helps you express your feelings, know others are hearing them, yet remain insulated from the fallout.
That said, it's rather embarrassing that lesbians and bisexual women are having it out on this blog about what does or doesn't count as biphobia or if it is or isn't real. You're not going to change each other's minds, and this isn't productive. Make a throwaway blog and state your case there. If you use the right tags, people are more likely to see it than they are from posts here. This is clearly a divisive and important topic. I say "important" because it's driving a wedge between members of our community, and contributing to a toxic atmosphere. So have it out. Discuss it. Whatever you might think of someone's position on it, clearly it's causing you both distress, and you both likely agree about most other things. Don't let an inability to understand another person's position on this topic prevent you from forming community. Let's all try for a little empathy. There are lesbians who've dealt with women trying to coerce them into threesomes(though I don't know if it's necessarily true that those women are bisexual; plenty of men pressure their girlfriends/wives into threesomes without giving a shit about whether or not she's into other women), and there are bisexual women who have had lesbians tell them they don't belong in the community or are somehow tainted because they've had sex with men. Both of these experiences are very hurtful. I would hope that radfems would be able to see another woman's pain and not get into a pissing contest over who has it worse. Pain is relative. A child skins their knee and starts screaming and crying, because it's the most painful thing they've experienced. A person with a broken arm is going through greater objective pain, but maybe they've dealt with worse, so they don't feel the need to scream and cry. If a woman or girl tells you that an experience caused her pain, and your next response is to tell her how much worse you've got it, that helps no one, and prevents you from being able to connect. Just. Have sympathy and empathy for each other, please.