I was focused on work and personal goals and finally forget about dating, that's when one of my bosses started leading me on and I don't know why

I was getting over a low period in life, found the stregnth to focus on work, better myself, being happy and bring a great attitude to work without focusing on finding a spouse or flirting or anything like that. Well. For some reason this attracted this married guy I work with. He was showing signs of liking me and kept checking me out all the time, blushing, getting tongue tied, getting nervous around me, smiling back and giving that "i want you" stare when we made eye contact. So after a while I started flirting back. (I didn't know he was married,) After about 2 weeks of subtle back and forth he backed off suddenly and told me he was married. Suddenly he wasn't nervous anymore, stopped blushing, gained all his confidence back and stopped being awkward when I walked into the room. And now I feel insecure and awkward when he walks into the room cuz I can't help but wonder if they were just toying with me? Now every time they see me they give me a look of pity? I'm bummed again because with that surge of energy I got to focus on work and myself and being happy was I was doing fine and my self esteem was doing great until they perked my interest. I got my hopes up and then crushed and just feel....led on I guess? I don't regret being honest and giving it a shot, but I'm not feeling good now and my self esteem took a huge nosedive. I guess a married guy led me own to boost his own self esteem at work and now that he knows I like him he is sort of laughing about it. I don't know exactly what happened, but I just feel really bad.

Is this like a common thing that happens in the workplace?