[21F] I slept with a guy on the 3rd date and he hasn't messaged me and ignoring my messages.

To cut this short I've had 2 amazing dates with this guy [24M] and the dates was going amazing, he was saying how he was having a great time and he said he liked me. On the third date we had some nonalcoholic and I invited him back to my home, we had sex. After we had sex I voiced my concern that he would just run away and use me. He didn't message me since that night so I messaged him asking if i have done anything wrong, he replied no he has just been really busy. I took the liberty of asking him out to watch a film in the cinema this weekend, he opened my messaged and ignored it. I know he hasn't been busy. I just feel so awful, I didn't think he would be that type of guy to have sex with me and then just ignore me and blank me. I feel used but I understand it takes two to tango so I only have myself to blame. How can I stop feeling so upset?