friends with ex makes me sad

I broke up with my ex 1 year ago but we are still friends. It hasn’t gotten any easier for me to talk to him. Everytime we see each other in person or call I wind up getting upset or crying. I’m not sure when it will stop. I don’t want to lose contact with him because I want to know about his life but a lot of the times I wish I could just tell him that i cant be just his friend and that’s it’s too hard. Sometimes I wish I could just tell him I’m never going to talk to him again because it’s too hard.

I don’t even know why it’s so hard since I was the one who broke up with him. I just feel happy talking to him and I guess it reminds me of being happy in our relationship and then it upsets me? Idk I feel sad being happy with him.

Is this normal?