I had this girl from work for a few months that i kept thinking about having a relationship with, but prefered to wait for something better.. My workplace is young and dynamic. people and girls around my age come work there. A month ago I went out with coworkers to celebrate wellfare from other coworker which is also my best friend at work. We had good time there drinking, and suddenly she started touching my thigh and hip, it felt good but it came out of nowhere haha Since that evening i decided I'm gonna ask her out, which i did a week after, she couldn't meet me on the same day i asked her so we rescheduled for a week after. In the meantime i acted normal. We met for the date and walked for a bit, we sat on benches at the beach, conversation flowed, no awkward silence so I'm thinking ok it's going relativity well i should go for the kiss. Forgot to say we were out for 7hours. We sat hugging on the bench and i looked for the kiss, i chickened out multiple times and decided I'm gonna save the kiss when we say goodbye. I kissed her later, she went for the hug and I bent over to kiss her, she was surprised but she liked it I could tell that. Even told me to send her a message when i get home. I don't go to dates a lot but i wasn't as excited as i thought i would be. The following week was hard ngl, i had anxiety and self pity that she might not even like me back since she barely spoke to me. And I have a problem to initiate convos with her on whatsapp/instagram (on IG I sent memes amd videos that she replied hours if not 1-2 days later).I noticed some coworkers that talk to her constantly, some of them are touchy, with others i see her giggle. I started to worry and feel sorry for myself that I couldn't even ask her out again,  evetually I did, she said she's busy for the weekend. Asked her again in the following week, and she already had plans, at first I thought I'm suggesting to hang out on the last minute. Couple of days ago my friend from work told me that she's not interested, and I'm not supposed to know this now, but she'll talk to me about it maybe. That... Bummed me out.. Because I feel like we have good enough chemistry, we both inexperienced with dating and I'm really thinking we could make a good couple. I know some if not most would recommend me to move on but that stings my ego like hell😕 To know I had her interest at one point is frustrating.

What do I do to gain her interest back?