How do I get my ex boyfriend to be more than a sex buddy?

Me and my ex have known and loved each other for nearly 3 years, although we wern’t actually together through a lot of this time, we both knew how we felt. We broke up 4 or 5 months ago and after a few weeks decided to go back as friends, I love him with all my heart and he knows this but he is sending me mixed signs. As it is now we’re more like sex buddies, but I want it to be more. I feel I’m being used, Sometimes he acts like he’s using me and it’s just for sex, but then other times it’s as if we’re back together, He even turned to me and said out of nowhere one night, “You know I love you right? I just don’t want to hurt you again.” ..so he goes from lovey dovey and acting like he cares, to absolute prick that acts like he’s using me and ignores me for a week or two.He even still brings me to family things, like over the christmas he brought me to all his pamily get together things even though they know we’re split up but it must mean something because he’s very picky about who he lets his family see him with.I get on great with his family, his friends, even him, I’ve never even fought with him only when he broke up with me, I don’t know which way it’s going and it really hurts me so much I would do anything to have him back I can’t just let him go.