In my social circle of 6 people ,there is this dude im going to call him John. He is the leader of the group, no one messes with him. One day i was just hanging out with my friends and John. John starts picking on me for no reason. After a few provocations I wanted to show that im not weak and pushed him (Im 15m 6'2" and he's 16m 6'2"). He then pushed me back but in a more aggresive kind. I panicked and just kinda laughed at it and changed subject (It felt so weak and cringe) because hes really stronger than me. The next day I could feel that my friends lost a little respect.

Soo my questions: How should I react if people with higher status or that just are stronger than me pick on me? What can I do to regain the respect from my friends? (Sry for bad eng. english isn't my main language)