idk what to call this

Sky
so i'm a very anxious person and i don't take anxiety mess or anything i'd just prefer not to. i get really anxious with relationship stuff and this is my first boyfriend. we started to almost make out the other day and it was great but i got scared and pulled away. now looking back the next day every time i think about it my heart starts to physically hurt. it's not like anxiety it feels different idk how to describe it. anyone have any tips or just words of encouragement i'd really appreciate it and please don't leave anything negative i already feel like shit