Sexual anxiety?

Not sure what tag to put but I guess that’s close enough. 18yo male there’s this girl I’ve known for a bit and I really like her but it seems like ole buddy doesn’t wanna get up when it’s time if that makes sense. My question is how to deal with sexual anxiety when it comes to this? My dick has usually worked just fine for other girls but idk I’m super attracted to this girl and I feel embarrassed when I can’t get it up, I get horny and it gets hard for a minute and then I get nervous and it goes back down. I haven’t told her that I’m having anxiety about it because that’s super embarrassing on my end I feel like. I don’t think it’s a self esteem thing because I know I can perform well but who knows Any help would be appreciated