Why can't I seem to get a girlfriend?

I am 21 years old, my ex-girlfriend broke up about 6 weeks ago. I am not bad-looking, I have a head full of hair, I am pretty fit and I do shave my face regurlarly. My hygiene is on point, and I am able to socialize well with people, I'd like to think that I'm pretty confident around women. Still though I don't seem to be able to attract nobody. Not since I became single. Whenever I ask someone out, they usually reply with that they don't have time, and then I never hear from them again. I really thought I was of above average quality, but maybe it's because I'm quite short, or maybe it's because I've recently became a little skinny. Haven't exactly hit the gym as often as I should have during these corona times. I do try to wear good looking clothes and I do style my hair, so it's not like I don't make any effort either. I've never had trouble in the past to get people to like me. But maybe I need to further develop my social skills, when it comes to the romantic and/or sexual aspect.

To the guys out there who gets all the girls all the times, or if you manage to get them at all. How should I improve myself, and what's the best way to build attraction with a woman?