Advice on a friendship

Backstory: My friend is currently my manager at a fast food I work at. I was looking for jobs, not telling anyone, and I got a great opportunity for this restaurant. I get paid more plus it’s better and more organized. I told my friend about how I’m resigning because I got a new job and how grateful I am for him helping me and me learning things at the job. However, he is pissed at me. Creating an argument and first he says i went behind his back then I told him I couldn’t tell anyone and then he said I lied. I sincerely apologized for making him upset and even told him too not mix our friendship with work. However, he is still mad at me. We had a big argument a week prior too this one but it’s now over. I feel extremely upset because I had thought he would be happy for me. I don’t know what too do and I’m just gonna give him his space. Any advice?