Why do I keep getting ghosted/ played?

Hi so I’m 22f and have been single for 3 years now, I’ve dated quite a few different guys and they have mostly all either really hurt me or ghosted me/ cut things off. I feel like I have no luck anymore and have completely lost my confidence even though I’m told that I’m a “pretty” girl. I only ever go to work and the gym, I’ve lost a lot of friends over the years and basically have no social life anymore. The only way for me to meet someone is online and it’s just going awful. I also work in a completely female workplace. I seem to either get used sexually or disregarded after a few dates. I don’t know what to do, kind of ready to give up.