Is it normal jealous of my younger brother?

first of all I'm almost 30 and my brother who's 17 just graduated from high school. I went to his graduation today and then tonight me and my parents dropped him off at school because the school hosts an all night party for graduating seniors. The Class of 2015 gathered together on the front yard of the school and were hanging out talking waiting for the buses to pick them up. Our car was parked in the lot for a good 20 minutes because my parents were scared of leaving him alone. I saw a lot of senior girls walking across the front yard of the school. I have to admit that every single girl there was cute, young, and adorable looking. And I was so jealous at how my brother seemed comfortable talking to some of the girls and how he'll have fun at the party. My brother is a lot more attractive than me too. I used to be confident in the past but my life has been a constant downward spiral since high school. And I realized I was jealous of my younger brother because he'll be getting all those opportunities that I wasted. I have no friends and I'm a virgin who lives with his parents. Also I'm only attracted to girls between late teens to early 20s, which is creepy enough as it is but will only get more embarrassing the older I get, especially considering how no member of the female race has ever expressed even the slightest interest in me.