Me [32F] with my friend (?) [25M], I didn't understand that he wanted to be with me and now he ghosted on me

Ok, It's quite strange and I feel really bad about it.

So... he is my ex-coworker. I loved to work with him, but because of 7 years age gap I've never saw him as a guy, but just a friend. He's a big introvert (he would say hi to everyone but talk only to few girls in the office, I know for sure that girls in my department didn't even remember his name, even if he came to our room once in a while for my support), but whenever I tried to talk with him, he was all smiling and his eyes were sparkling.

He knew that I've wanted to leave this work soon, and he added me on facebook. but after that - nothing. I don't really remember how he behaved on my farewell party. I was spending a lot of time with a lot of people, and I wasn't romantically interested in him (yet).

Few weeks passed, and one guy had farewell party as well at my previous job. I went there, and then... well, after awhile, when we went to a club, he sat next to me, on the armrest, and he hold my hand for all this time. I thought that he did it because we were a little bit drunk and I've never thought about it more. But it was a nice feeling and I remember that once I looked at his lips, there was this urge to kiss him. But once again, I thought that it's only alcohol in my blood, not real me.

fast forward, when we've met he told me something along the lines that he would like to spend some time with me and I told him that we can meet next week because I will come to the office - this time I couldn't go with him because I already I was going to some small party at my friend's home. I saw his sad face, but I thought that it was just because he wanted to talk about something. He was always really nice to me, helpful, but he never initiated contact outside the office (well, this one time he told that he want to go out with us), so I've never thought that he's into me.

Last time when we met he hugged me really tight and started to talk how he admire my beauty etc. He started to talk about it in front of other coworkers so I didn't think that he wanted to say something important. I'm not really good at dating, I didn't date for 10 years (because of health problems and because of my introvert personality, it's really hard for me to meet new people), so I assumed that he talked about my support when I was s till working with him. I hugged him, he hugged me, but I didn't respond to his words. He tried once again, and still... I didn't understand it. He even asked if he can talk to me about it once again, later, and I said - yeah, sure - and smiled. Then when he was leaving he hugged me and kissed my hand, telling something like that: please, give me at least that kind of kiss. After that I started to think about it, I asked my other coworker (who heard him telling me this "beauty" thing) if he wanted to say something to me, and she was mad at me that I didn't understand it, because he was really straightforward.

After that I've started to see him differently. After awhile I knew that he would be a great guy to date (smart, witty, I admire him, and I feel really comfortable with him). So I've started to chat him up on facebook, he would respond with nice words, but not so fast. But I don't blame him, he works really long hours so it wasn't an issue for me. I've tried to be closer to him and I almost, almost did it. He even gave me some light compliments, but... something happened. He promised to help me with something at my current job, and it would be only him. But some other ex-coworkers heard that he will help me and they offered their help as well. I thought that I should tell him first about it, and... after that everything fell apart. He wouldn't respond on my messages, or if he wrote something, it was just one word/sentence, but nothing flirty, just a formal talking.

I didn't want to write to him about my actual feelings because I've wanted to talk about it face to face. And there was one possibility. I organized a party at home, and he was invited. He told me that he will come, even when he started to stop responding to me, he confirmed that he will come, and wrote "see you in two weeks! :)". So I've waited for this party like crazy, but he didn't come. I wrote to him that because he didn't come he should buy me a beer next time, but he didn't respond either. I was so desperate that I tried to call him to explain everything, but he didn't answer the phone.

I know, it's all my fault, I should tell him sooner that I didn't understand him at first, and that after his words I've started to see him as a man, not as a kid, and I've started to have feelings for him, but I don't know what to do now. Part of me tells me to move on, but other part... well, I feel like I have to do something, to explain myself. I know that our talk was few months ago and after that time he could simply forget about me, but still... I fill that it's my fault. Ok, I tried to contact him, I offered to eat lunch together, but he didn't respond (but it was after telling him that those two other coworkers will help us as well)

tl;dr: I'm blind to compliments and flirting so I didn't understand that my friend likes me. I made it worse by my bad decisions and I don't know if there is hope to fix it somehow. He's ghosting on me right now and I don't know if I should explain myself to him. If yes - how?