Can this be fixed at home?

If you say the yoke has moved forward toward front of car, something is horribly wrong and you can`t just tighten the nut.
Make the shop do it right or full refund and cover any damaged parts.
Maybe I can relax now that Murphys showed up at your house and finally left mine:D
The only way the pinion can move forward is that the big end bearing was never fully seated or race too, but a 1/2 friggen inch?
Good luck:happy1: