I need your help!

So I was with my ex for four years and we broke up, he then got a new girlfriend and we didn't talk for about 3-4 months, then out of the blue he messages me saying he misses me and wanted to see if there was any chance of us getting back together as he realised how much I meant to him, he told his girlfriend he wasn't over me so he had to finish it with her. So we got back together and then he messages me the next morning saying he's not ready, he needs to sort his life out and become happy again before he involves himself in my life again...I'm so confused! I've cut a long story short btw!