Why is my boyfriend mad at me?

Okay so me nd my boyfriend lives in the same state but different towns.So he was coming to see me last weekend but i had other plans dat was planned for a long time so he said i understand so i didnt get to see him dat weekend. Then when he came down last week i had plans again to go birthday shopping for ma BFF! so he asked me why cant i spend any time with him i am always busy so i might have been cheating on him. which i did not cheat on him i just had other plans and ever since dat day i have not talked to him cause he is mad with me and idk why HELP!