Friend in grad school confessed feelings, I don’t feel the same.

I (24 F) met my friend (21 M) at the start of the school year. We clicked quickly, we studied together, FaceTimed, hung out but I always saw it as platonic. He had a girlfriend when we met, and I casually mentioned guys I thought were cute, so I thought the vibe was clear.

A few months in, him and his girlfriend broke up. Later in the year, I told him about a guy I was talking to. Shortly after, he confessed he had feelings for me. I was totally blindsided and told him I only saw him as a friend. He said he didn’t want to be friends anymore, but after a few days we talked and agreed to try again as friends.

Fast-forward a few months we’re hanging out as usual, and he admits his feelings have only gotten stronger. I told him maybe we should try no contact because I don’t want to keep hurting him, but he’s upset and keeps insisting we stay friends.

I truly value his friendship, but I feel like we’re stuck in a cycle where I keep unintentionally hurting him.
TL;DR: Became close friends with a classmate who had a girlfriend when we met. After his breakup, he confessed feelings. I only see him as a friend, but he keeps wanting to stay in touch despite it hurting him. Thinking about going no contact should I?