Dating life suck...

So I worked with this guy. Me and him had a great vibe together. we were doing some very heavy flirting but I never pursued him cause I don't like messing around with people I work with. Anyway he quit. Been gone for a few months. Friends encourage me to talking to him again and I gave it a shot asking his friend for his number. Asked him for a date and he straight out decline no explanation and no reply back. Rejection hurts. I just hate my mind thinks of the thousands of possibilities of who he could have told or seeing his friend come Monday if he told him. It took me awhile to work up this courage and to have so many negative thoughts and feeling that come behind this rejection just make me want to crawl under a rock and lie there....