There's this old fashioned way of communicating, it's called face to face discussion. Try it.
HI! I can not stop thinking about him but he ignores me. He texted me after more than a month saying he missed me but now it seems that he disappeared again. What should I do to get his attention back?
It sounds like youre being used here as in hes keeping you around in case he needs an emergency date but he really isn't all that much into you. You need to just move on past him and don't look back unless you plan on going there. If he sees you moved on and really does like you , he will come after you but I don't see that happening here at all. Move on and good luck
If the person likes you, you shouldn't have to chase them. Find someone who is available to you and straight talking about their feelings and intentions.