So sorry you're going through this! Listen to MrBond. Consider writing down your thoughts, expectations, boundaries. If J is truly willing to commit to R, then he needs to accept your concerns. Also ask him to write down his thoughts, expectations, etc.
Don't cancel your C appointment. Think about what you'd like to get out of the session. Seek advice from your C. If you're not getting what you need, think about looking for a different one.
You won't solve anything right at this moment, so use that energy to write down your thoughts. Then tomorrow, when you're calmer, review what you wrote down to see if you still feel the same way.
