everyone has their own habits before going on stage. . you just got to find what calms you and relaxes you. .  for me i always have a carton of milk and i pray before i go up there and play. . . lolz. . . and of course warm up. . . usually i isolate myself and just do warm up stuff. . . and do some stuff. .  lolz embarrasing stuff . . xD at least i don step on a plate of crap. .  i forgotten who but ther was this 1 guitarist who has this litter box full of crap in it . . mud, shit, condoms, thrrash food and stuff then he steps on it before stage. . lolz

stage fright can be overcome by performing alot . .. just play alot of gigs and you'll overcoem the fright. . . either that or try and shut our the audience =D
try working small venues and slowly gig at bigger ones. . . schools are a good way to start. . . IU's and stuff. .

As for lyrics i guess you just got to really drill the sogn to your head and try not let the fright stress you out till you blank out. . . it's more of experience then anything.  . . i'm sure the rest of the guys in the forum who play live can tell you that =D