A man has fallen in love with me - and even told me so, but we can never be together. We were team mates and tried having a relationship, but he destroyed it with criticism and harsh judgement (and said terrible things I will not repeat on here).
I put on a brave face for work but I was crushed and can never give him my heart.
However, we are good friends and enjoy each other's company. Though he hurt me, I do not want to do the same to him.
I cannot be with him, but am terrified of breaking his heart. He does not attract women easily and I do not want him to give up just because he can't be with me.
Please tell me how to let him down gently.

I agree, it's better to be direct but gentle.