He said WHAT?

So I've had this FWB on & off for 6 years now. We dated 9 months ago for about 4 months & got pregnant. We ended up having a miscarriage & then broke up over a misunderstanding. We've just started fucking again at the beginning of June, and out of nowhere he just texts me saying "I love you". I'm at a loss of what to say lol. I mean, don't get me wrong.. I do have love & feelings for him, but I thought we were just fucking? So I've been keeping my feelings out of it. This is the only time he's ever told me he loves me.

How should I take this? What would you all do?

Edit - I do want to be with him. I never said I didn't, I just don't want to get hurt either. He's 40, I'm 25. He has an 8 yr old & I have a 1 yr old, and he's the only man I've ever let be around my baby, literally my child's bio father has never even seen said baby. He was there during my pregnancy & childbirth. He isn't my child's bio father, but my child has started calling him 'Da-Da'. I told him I love him too, and he just sent a winky face back & said he's going to sleep (he works 3rd shift). The thing is, when we broke up in Feb, I had the miscarriage the week after. Then in March, he came back around for a couple days & when I told him it was too soon for me not to have my feelings in it still he cussed me out & sent me pics of another chick saying that was his new girl & he was going to marry her & blah blah blah. I guess they broke up, but I'm not entirely sure bc he hasn't said so. But he did apologize for being such an ass, and he's been at my house every day for a few weeks now & he's never on his phone or anything. He didn't cheat on me when we were together. I'm just confused on what to do!