I don't get this at all it's confusing ...advice please

It was hard enough falling for someone and not letting my own insecurities get in the way because I profoundly cared for this person in a way I just haven't experienced before , I am working through that whirlwind patiently and with a sense of perspective and I thought it was all going to be ok but man was I wrong !!!The last few days have been a whirlwind of hot and cold messages which led me to take a step back only for him to message me to make plans which I said yes to.Subsequently I initate to ask about his day and I'll get nothing for days or he will text but then suddenly leave me hanging. It's a few hrs before we were supposed to meet up and I have no confirmation ....nothing !!!It's bad enough trying to protect myself but then opening up to someone and feeling vulnerable , but then to have to deal with this sudden hot and cold behaviour ....it hurts and now I'm just confused ?What the hell is going on ....why is he behaving so differently and how do I navigate this ?