relationship

I broke up with my boyfriend on the 18th of March and he moved on the next day,I've been talking to him,even yesterday we talked,the thing is I'm unable to move on from him the same way he did On Sunday we flirted and later that day i told him that I'm keeping my distance because he's in a relationship,honestly it's hard to forget about him

I am 23 years old I never had a gf before and never tried Until I entered university I noticed all around me have gfs constantly So I tried to get one but for the past 2 years all my efforts didn't work Which caused me to have doubts that I may have a flaw If anyone experienced this before what's your advice to me ?

I am a doctor undergraduate i need to talk to a girl any one who i like at first sight (I've never entered a relationship with a girl never talked to a girl comfortably) I can't start a conversation Too shy to start Don't know what to do please i need a solution