Friends with benefits problem..

My ex recently got in touch with me after a year of us not speaking, after talking for a while we agreed to become friends with benefits at the time it seemed like a good idea, we both agreed that it would be nothing more than that and we were both fine with it. I'm starting to struggle now though, we were together for over two and a half years, Only now I'm starting to realize that I still love him and it's getting harder every time I see him to not blurt it out. I just don't know what to do, we went from 0-60 straight away, I was the one who broke off the relationship and I've regretted it since the day that I done it so when he got back in contact with me it was like everything I've wanted coming true. Whenever we're together it's like the past year never happened, like we're still together which is the thing that I'm struggling with the most I think. We'll be sitting there watching a film and all of a sudden he will grab my hand and start holding it, hug me or kiss my forehead. I'm not sure how to take all this? He's told his family that we're talking again and they told him to ask me to come over but I really don't want to over complicate it all. I'm just so confused, at the start I was so scared of him leaving my life completely, but now I'm really not sure if I can keep doing it, knowing that he will find another girlfriend and then I'll be on my own especially if my feelings do keep growing, he was my first love. I'm still really close with his mum and even when me and him weren't in contact I still saw her whenever I was about but I don't want to mess that relationship up too, she was my main support that helped me get through our breakup last year.