I'm crazy about this girl in my office! Should I make a move?

Dear love guru, Hope u are doing well.  This story starts in 2018 when I was in my 12th. I had a huge crush on this junior girl. This girl is very intelligent and she used to get very high marks. So I took that as an inspiration and started working very hard on my academics. I started to read like a maniac and that worked and I got seat in a very prestigious college hoping she would get the seat in the same college but unfortunately she got seat in other state. I was disappointed. I was shy and never talked to her in my 12th and thought I lost my chance of talking to her ever again. But fortunately after a year, I found her insta and mustered my courage to chat with her.  Although it was awkward initially, we became good friends (I guess so) and used to chat almost daily. She is really a charmer and she chats so nicely. She is a great friend but I never had courage to say about my feelings. She used to talk about her friends, her new college and her cats and so many things about herself and as I am her senior, I used to guide her and talk about my daily experiences. We had great time talking to each other on insta, WhatsApp and even snapchat. Heck we have a Spotify playlist Collab and she even included me in her private Instagram account as a close friend (u know that girls do have spam accounts for close friends) and I was wondering whether I'm just another friend or close friend or anything more.  This continued like for many months and we chatted very well in the lockdown. I never met her or called her, we just chatted( I'm a shy guy and not so good at talking to girls). Feelings aside, she became a really good friend to me and I don't have many friends. I never said her about my feelings, fearing it would destroy this great friendship I was having. But recently she was not responding properly to my chats( I never misbehaved in the chat ). I do believe she is seeing a guy whom she met recently but I don't know whether that is a relationship or just friendship.  I was disappointed but hey it's her life and I was u know just continuing my life feeling sad sometimes or just trying to forget about her. And recently she completely avoided my messages and I was so hurt(I do have some self-respect right). U could say this as a one side love story. But this is so hard. After all she is my first love and this started affecting my academics. Should I move on or should I just continue trying to talk to her so that hopefully she will talk to me like she used to before. I don't have any problem continuing but sometimes I feel what's the purpose since it is going nowhere.  Please give me any valuable suggestion. Sorry for the long story Thank you  

I am a second year student (male), till now in my life i never been i any relationships actually to say i never attracted to anyone, but during the college i met a girl, we started talking, one day while texting she told me that "I heard something I want to ask u.. Something like u likee me?" after that with some fear or i don't know what to say that feeling but I had told her that yes. but then she told we can be only normal friends not to expect more than that. i dont know what to say but i told ok. then even after that we had talk but now a days it reached a point with no replies on chat. i have tried to move on, then suddenly i miss her. as she was my first girl (not even into relationship) that i had some feelings.

I’m 36M, I met a girl in my office, who works in the same department. It was love at first site for me, but I was scared to tell her that. As time passed, I used to strike some casual conversations with her or her team to connect with her and there were some clear signs that she liked me, for example, she would call me or text me why I’m not talking to her if I didn’t message her for some time (a week) or she would ask me if I was coming to office as we were working Hybrid if not she would also not come to office. But she always refused to come out with me for a movie or date/meet saying she had a very strict family and cannot come out other than office. I used to think that this was a real thing. But all this went on until her birthday arrived. I got some gift to give her on her birthday only to know that she suddenly stopped talking to me, no replies to my messages, calls or anything. At first, I was bit concerned if there was any problem or if she was in any trouble. But little did I know it was not the case at this time. After few (many) attempts trying to reach her. I though maybe she could be busy or something and I understood may be if I did not disturb her, she might call back. Time went on I again met her after 4 or 5 months in Office with no contact. By this time, I had already realised there was something wrong and she had already lost interest in me. But still I felt like I wanted to have a closure on this and I went on and gave the gift and proposed her, that is when she told me that she was in a relationship with some other person for 4 years. This blew my mind to pieces, as I was thinking why would someone shows any sort of interest on someone when they are already in relationship with some other person. I tried to move away from her after this incident, but fate we still are working in the same department and that I have to see her more often than not. I still have strong feelings for her, but I cannot show this to her and worst act normal. Whenever I see her, I want to talk to her and If I talk to her, I fall for her again and again. But she is happy and casual about all this as if there was not casualty in whole of this thing. Even now she asks me if I’m coming to office so that she could meet me. So, through all this, I have some questions 1. Why does a women show any sort of Interest on someone else when she is already in a relationship, so she can use me as a options and throw away when done 2. How do I move on, as I did not love her for some superficial features, rather I really liked her character, and that is the worst as I feel like I’ll never be able to find anyone like her in my life. Feeling down for a long time now. I’m already 36, feels like all the doors have closed for me.