What do it means when he says this? "forget about me, dont hate. you are going to get nowhere with me.. move on' but days later messaged apologizing and saying they are ready to talk now. and posted 1 thing on tumblr saying "i miss YOU" a few mints later when i didn't reply back.

When he says forget me and move on he means it, at that time, then he wants to talk and he also means that, at that time.  This adds up to you being on a roller coaster of emotions because for whatever reason he doesn't want to commit to a relationship with you.

Take him at his word and move on, it won't hurt him to find out that you're not just going to jump at his beck and call.  It will be difficult to do this if you really like him but what if you do get involved with him and he still does this from time to time, how are you going to feel never knowing when he's going to tell you to move on again?

Find someone who values you and your feelings, when someone really cares about you they will want you around all the time they won't play these games with you.  You deserve better than this.