what do i do and why is my bf acting like this?

me and my bf have been dating for i think 2 or 3 weeks now. in the beginning he had been super sweet and texted me all the time everyday would say good morning and goodnight. he is very social and has lots of friends (including other girls.) we go to the same school and have only talked ONCE in real life which was just a few sentences until he had to go. he told me he gets nervous talking to me and around me so it’s hard for him. starting yesterday he got super dry and didnt text me barely unless i texted him. i asked if he was mad and he said no but i believe him. today i saw him after school and he kept looking over at me but never went up to me (btw he was with his “home girl” 😒) it just honestly makes me feel sad the way he never talks to me but talks to other girls easily… and i’m scared cause he has been super dry. today he hasn’t texted me at all and it’s almost night time. should i text him or just wait for him to text me? i know it may seem like i'm overreacting but i really like him and don’t want him to leave me with no explanation like past relationships. so what should i do in this situatio?