hi everyone

I'm new to this so bare with me, please?

I'm a very shy person and I won't make the first move to meet or talk to somone new. And when someone does try to talk to me, I'm so awkward. Then they stop talking to me. (either the start of friendships or relationships)
I'm 20 and I'm always being forced into finding a boyfriend because I'm the only one left not getting married or having kids. But the thing is, I don't want to be married or have kids right now. Of course I want that in the future but for now I just want someone to like me for me and not have that lonely/depressing feeling. I have this constant thought that I'll be forever alone and I'm not good enough for no one. My self esteem is so low. Sometimes I feel so ugly that I don't leave my house. My anxiety has gotten in the way so many times. I hold everything in, and don't say a word. I just pretend I'm happy, but I'm tired of crying all the time.
and I can't say anthing because I don't want them to think I want attention, when that's the last thing I want.

Here's my almost but fail relationship story...

I was told that a guy from work liked me and wanted to get to know me. We exchanged numbers and we would talk during our breaks at work. I was so nervous, but happy because I haven't been in a relationship for 2 years then. We went on one date (I was extremely nervous, that I got sick before) and it went well. I was proud that I actually survived my real first date. We continued talking and discussed being a couple after hanging out more. I was down but I would always avoid the dates. I would come up with excuses. I don't know what was wrong with me. "Was I not ready? But I'ved been waiting for this for so long?" I always would have discussions in my head. It turned out that I ended things with him.
He was upset and told me he wished he knew before he wasted his time on me.

At work when he would see me, he would smile but I would put my head down right away. I always avoid my problems.

But after a couple of months of avoiding and pretending we didn't know each other I couldn't take it. I missed him. He was such a good guy and you don't know what you got until it's gone.

I text him and I apologized that I messed up and I was willing to try it again if he wanted. After that, we started talking again and everything was going good. I was happy again and I even felt more comfortable around him.

The thing is, he wanted me to be more expressive in the way I felt and wanted me to be all on top of him. With my anxiety, I hold everything in. I'm not the best person to explain my feelings or be touchy feely with a guy. He stopped talking to me ...

I didn't do anything about it. I'm not one to chase boys.
A couple weeks passed and he left me a message saying he's just going to prentend we don't know each other and he's done. He said that he put all this effort in, and I didn't even try. That hurt so much.

I just text him back saying, I wish him nothing but the best.

Now I'm here forever alone once again.
He doesn't even look twice at me at work.
It sucks that I know that he moved on and I'm just sad once again.
Sometimes I just wanna text him but then I don't wanna seem desperate. I don't know what to do at this point. I hate seeing him at work.

Any advice would be appreciated.
Thanks for reading.