I feel broken

I have had feelings for the same guy for 10 years. He knew this. Some of those years, i didnt see him. Bu i decided to message him, see how he was (i saw him in public and couldnt stop thinking about him). He messages back. The first night (last week) we made out. My first kiss ever! He told me he didnt want a relationship, but if we started things off this way, doing physical stuff, he wouldnt rule one out. So i tried. The second night, he felt me up and i gave him head. I know, too fast, too soon. But i wanted him and thought if he could just see how willing i was to go out if my comfort zone, he would feel something. But i wouldn’t have straight up sex until he showed some signs of emotional attachment.

Then he didnt talk to me for a couple of days. Told me he was moving and not talking to anyone, so i gave him his space. I told him i was here if he wanted to talk and left him alone.

He messaged me last night. He kept trying to steer the conversation to sex, and i was supposed to see him. But when i showed a reluctance to letting him see me in my underwear, he informed me that he and his ex have been talking and he wanted to get back together with her. I was shattered and told him how hurt i was. He kept saying sorry and he didnt plan this and dont post anything on fb because he didnt want trouble with her.

Ever since the beginning, he didnt want me posting anything. I thought it was because the last time we talked, my friends cussed him out. But i think he had been talking to her the whole time.

I want to be vindictive, but i told him i wouldnt and ket the gurl find out on her own what kind if ass he is. But, she doesnt need to be hurt, too.

I want him to understand the gravity of the hurt he inflicted. I want her to not get hurt. What do i do?