How can I show a guy I don't care anymore?

I am being honest.

I still love him and probably always will but he thinks I am still after him. We were (or are) still friends after our break up (that was 2 years ago) but we had a huge fight (we often have fight cause of my feeling and always become friends again). During the fight I had told him thanks for the birthday gift (my b day was 15 2 20 days before the fight) for the heart breaks he gave me. After a month after the fight I had told him I was sorry for being mean and I didn't really mean what I said and I shouldn't have been mean to him and that he is safe with me now. He writes back to me that "u are a friend please stay in the friend limit that's all I want to say." I had wrote back that "I only wanted to say sorry that's all." I do love him and I do want him back, but I have decided to let him go but we will see each other and I really want him to see that I have let him go and he doesn't matter to me.

Also note that I have crossed the limitation of friends but after he did. He always flirted with me first and he always started with the sexual conversation. I admit I only had started one conversation but all the others conversation he had started. He always took the first step and I followed.