Ok for what it's worth ....
Your marriage didn't work out.
You had good moments, happy moments (even the most dysfunctional relationships have those).
But in the grand scheme of things it wasn't right and you parted company. You went your separate ways and divorced.
Now you find out the man with whom you weren't happy has met another woman and he's sleeping with her.
Your reaction to this news has overwhelmed you and you are starting to think irrationally.
What you are experiencing isn't love. This reaction of yours isn't love. It's jealousy (primarily) but that jealousy is mixed up with lots of other emotions, familiarity, assumption, loss, regret and fear.
No you don't 'love him still'. You are just jealous. Jealous with lots of past history and mitigating circumstances of course.
This emotional, heart wrenching, tearful reaction to the fact that your ex of two years is sleeping with someone, isn't about love, and it doesn't mean you need to tell him how you think you feel either. What would the point of that be? You are two years separated/divorced.
If he is into his new partner then he won't welcome this declaration from you .. and if you are two years separated then there's not a snowball's chance in hell of you achieving anything from such a revelation.
HE LIED, WAS CONTROLLING, VIEWED EXTREME PORN .. AND MORE.
Remember all the reasons you divorced him .. and while he's enjoying this first flush of whatever it is he is feeling for his new partner ... ultimately it is she who is going to have to deal with all the issues that made you separate from this man in the first place. The poor woman/girl doesn't have your experience, insight, knowledge and past history with him. All the things that made you split from him ... are now her problem not yours.
Be grateful for that and see this for what it is. Your porn viewing, lying, controlling ex has got himself a new girlfriend. Be grateful it's not you.