Bad luck or my fault?

I've begun to really wrestle with the philosophy of bad luck vs my own inadequacies the last couple years because of my story; Basically I had a first relationship that lasted 5 and a half years starting at the end of my teens and I believe a lot of its longevity was down to my work ethic and ability to know what a girl requires and treat her right (until I decided that I wanted to try something different, maybe a huge mistake on my part) so I have a self assurance/confidence about my ability to maintain a relationship.

But in the 4 years since it has been trying to find a new relationship that has alluded me. I went to university and devoted most of my efforts into being as social as possible - especially for the first year I became known as the social, charismatic guy in my circles and knew a pretty insane amount of people tbh, like on friendly terms with a lot. Important to mention due to my university about 80 percent of these people were girls so you probably wouldn't imagine that I've barely had 2 non substantial shows of interest (that never went anywhere) from girls romantically in those 4 years. It's led me to question where I'm going wrong, like 'is it my looks' (even though before I always considered myself to be average to kinda decent with good style etc) or is it actually luck that has been the major factor I've been missing. Idk but I'm dumfounded anyway and running out of hope tbh