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Komiii,baka asked question about make a picrew

how tf do you make your arm not numb and sore, i cant read my manga without having to move my arm so its comfortable or rolling on it and screaming of pain into my pillow(its my left arm btw+first shot) like damn, i knew i was going to be sore but not like this... But fr how do you make not feel like this? Oh and is the second shot worse???!( ̄∇......