i need help freestyling

okay i am having trouble freestyling i can be walking around doing a daily thing and freestyle brilliantly almost like eminem. but when it comes to actually HAVING to do freestyle in front of a friend then i cant think of ANYTHING and i freeze up and can barely talk and when i do freestyle actually saying it i get tongue twisted and have trouble saying what i want to say.
so i am think maybe practice a bit more actually vocalizing my music and practice in front of friends. does anyone have an idea and please dont start shit with me i guarantee youll lose
because i have had a bunch of punks starting shit

itght nigga wut u do is simple u jus keep going along wit it even if u do mumble or sum 1 cuz u c i made up a freestyle bout where i live and it goes


Im Comin From That C-town were u hear sounds like click squeez pow get down or u dyin keep a tite iron i got the coke flying like brids not the ones with feathers im talkin weight like bird and might get served if u proper or somting or find your nerves on the curb if u a cop or something!!!

there is already a thread reserved for this topic. refer to it