Try calling him or texting him from one of your friends or relatives phones. If he picks up or replies then that’s proof that he ignored your calls/texts on purpose. You can get a free Google voice number and call or text him from that number and see if he responds.
If you don’t want to do this then just give him time. If you don’t hear from him at all then just move on. You will meet a better guy. You apologised. If he wants to stay mad then that’s on him.