Boyfriend left me by a note to move across the country

My boyfriend (19) left me (18) to go back home and start a band with his best friend. We have been together for a year and a half. I guess he was thinking about this for a full week. I found a note on the fridge explaining why he left. He claims he still loves me and that we are together but idk what to believe. My heart wants to believe him but I just do not know. How do I get through this? It feels like a breakup but I guess it's not.