Hot and Cold Treatment

My ex and I broke up 7 months ago, we had no contact ever since until he reached out to me all of a sudden last January. He called one day asking how am I, and him reminiscing the things we did when we're together and joking around that we should meet again. The first time that we did talk I already asked him where is this going because I know that he knows that I still love him and he told me to take it easy. It goes on like this like every 2 days and he'll just call all of a sudden. and then come March, he just like stopped calling me til now, we're also workmates and whenever we had a meeting the past few days I feel like he's acting cold or like he didnt know me all over again like the treatment we had few months after break up. Its just so confusing and I feel so pathetic all over again, i thought we were building something or taking it slow to start over, i don't wanna be the first to contact him, i am so tired and exhausted to still force myself to him. I know he's a good man and he'll never intentionally hurt me or maybe he's confused as I am but I'm really having a difficulty on what's going on in his mind. Please enlighten me. ps. We had a decent proper break up and there's no third party, he's having quarter life crisis and just want to figure out things alone