My long term boyfriend has left me?

we have been together just over 6yrs.we hadnt been seeing much of each other because of work and he had been a bit snappy but i just thought he was tired. next thing i know he's left me a note saying he doesnt love me anymore. he's avoiding me, wont talk properly about it, and doesnt want to come near our home. he says he's tried altho when i dont know, and there is no chance his feelings will change.im going out of my mind, i am devestated. im sure if we spent more time together things would be fine again but he is running away from the situation. i dont want to push it or seem needy but i cant give up on us that easily. any suggestions what i should do?