Sadly, I don't think it makes a difference: this relationship is so rife with conflict, obstacles and distrust that I really don't think you can make it worse.

Just read what you've written...

none of this should need to be said in therapy. I'm sorry you're stuck in such an unhealthy relationship, and that you're even paying for the email portion...

it's like... you could find an abusive boyfriend for free for this garbage-laden treatment.

If you're determined to continue, well there are advantages either way: sending now gets it off your chest AND gives her time to deal with her reactions, which are likely to be very defensive given what I know of her. The advantage to waiting though is to better convey your vulnerability, which won't come through via this message and you may feel more anxious after sending if she doesn't reply or doesn't reply well to this as she hasn't replied to your previous message...