PLEASE HELP!!

A friend asked me to just casually date.
We are hs friends and he confessed that time but I turned him down politely. Well, no hard feelings tho and continued to be friends and lost contact at some point. After several years, we sort of got in touch again. U know just the little chat updates , advices about his recent break up and shared interests. Then today, just asked me if I'm okay to casually date.

What does it mean? Does it make sense that I told them I need to think about it? I mean, I had a bad break up 2 years ago and still healing so i feel guilty using him at some point. He told me to just enjoy and not to worry but here I am doing the opposite. Are my guilty feelings invalid or u know overreacting? Please help :(