You should either have walked away from the friendship, or done nothing. Cause now you lose the friendship no matter what.

If you cared about her as your friend, and not as someone who you feel romantically entitled to, then you'd support her decision and keep supporting her autonomy. You don't get to force her to do anything.

You did something manipulative, which is what you're saying makes Felix a bad person.

If Felix is a bad guy for being manipulative, what exactly is it that you think you did?

To be blunt, you are the walking red flags person here.

There's no such thing as the friend zone, because you're not entitled to more than being a girls friend. If you can't handle being her friend that's fine, slowly disengage the relationship. Don't throw a tantrum and pull an ultimatum. Remember she doesn't owe you anything, so you're lucky to be her friend. But you have decimated and betrayed that friendship.

Secondly, Felix is allowed to be confident.

Thirdly you had no right to intervene in their relationship in such a deceptive and manipulative way.

You have a lot of work to do on yourself. What you did is unacceptable. Try and learn/grow from it.