I should just be a bitch and end it
You are not being a bitch.
You are at limit. Everyone has personal limitations.
If he's offering you a change to your shared marriage that you are just not willing to participate in? You say "No, thank you. I am not willing to do that."
That is not being a bitch. That is clearly stating your position.
He could process his disappointment like an adult. You both could calmly discuss appropriate next steps.
But if he's badgering
you and haranguing
you to do something against your will?
Guilt you into it, pressure you into it, etc? Then he is behaving like an immature jerk.
That's not you being a bitch!
And YES. You could choose to terminate this relationship because he does not meet your needs.
What's so great about him that you wanted to be with him putting 19 years of your own wants/needs on the back burner?
Again, I am very sorry you are going through this and are angry/resentful.
But NO, you do not have
to polyship against your will. Anyone telling you that you are somehow "less than" for not wanting to do things against your will is a jerk!
If you are thinking of terminating, I suggest a time out to get a cooler head. Making major Life decisions hot head is not a good way to go. Maybe you want to talk to a lawyer about how to split effectively?
But if you have money in joint? Could think about removing 1/2 to your own name only ASAP so you have guaranteed funds to live on in the "transition" time of a break up. Some jerks decide to play the "lock you out" game to "punish" you for not doing what they want. They try to close you out of your finances and then you find you are screwed because then you don't have access to your money to hire a lawyer to chase them around in court with! Sad but true.