Advice?! What should I say?

So I met this guy that my best friend had been trying to hook me up with forever. It’s her boyfriends best friend. We hit it off. Everything was going AMAZING. After a while he asked me to be his girlfriend and of course I said yes, I’d been single for a year. He met my son and they were so good together. I felt something different for this guy and he felt the same for me. We both agreed we were falling in love. Then one day out of no where he said he needed to take a step back and think about things. We didn’t break up but I respected what he was feeling. He came over one night and we talked about everything and agreed to work things out. He said he’d give me his 100%. Then that same night he texted me and said he was done, that he was afraid of hurting me. So fast forward a week... last night he sent me a text finally admitting that all his feelings were true (I’ll attach a screen shot). But he still doesn’t want a relationship. I just don’t know what to do or say to him. If he feels this strongly for me, I don’t understand what’s holding him back. I’ve been so heartbroken.