I'm upset about my so using our open relationship
What exactly is upsetting to you?
My partner is not following the rules we set when dating other people
If you are not happy about where your relationship is heading, then you should just end it. There is no reason for you to waste your time and effort. You could be finding true happiness with someone else instead of being depressed and mad.
It's all fine, even though he was hurtful because he was dishonest with me.
I think that you should both be on the same page about the exact boundaries of this relationship. I still think that if you are not happy with what is going on, the best thing to do is just end it.