Started sparring muay Thai first time last night. 5 rounds: 4 fighters and 1 beginner. Now one of the fighters was much smaller than me and I had no problems. Likewise with the beginner, made short work of him I'm happy to say. But when it came to partners that i know have a big advantage(experience,speed,strength,clinch) then I just kinda stood back and couldn't string any combos together. Can anyone advise me how to break the mental barrier.