How am I going to get over this ?

I started work at a jewelry shop in my hometown. I was really excited and grateful to have my first job at a high-end retail shop. But I soon found out that it was going to be much harder than I thought. The workplace politics were fraught, to say the least. My boss was extremely rude and impatient with me for my first two shifts, and I went home thinking that I never wanted to go back there again. However, the next day when I wasn’t there two of my colleges one of them an older woman and the other a young man (who is also the boss’s son) spoke to him about how he was treating me. The young man according to my older female college ‘really laid into him about how he was treating me. Saying that I was a really smart lovely person and that I needed to be treated better, and he took it upon himself to train me. This college also told me that ‘he really likes you’. I thought it was super nice that he stood up for me partially when he had only met me the previous day. On my next shift, he was really kind and helpful to me. I developed the biggest crush on him, I knew it would be a terrible idea to act on it as workplace romances are never a good idea. But I just couldn’t help it. However, he wasn’t always there when I had a shift which was really frustrating because he was supposed to train me so I was competent enough for the busy Christmas period. I found out that he drank heavily and also used drugs, yet another reason not to get involved. Eventually, my boss stopped giving me shifts because he didn’t have the time or the resources to train me. I am still really hurt, embarrassed and ashamed and feel like a complete failure. I still keep obsessing over this guy and it’s pathetic, and I can’t bear to apply for another job. How am I going to get over this ?