Shot ncr guy by accident and now im vilified done a job for them but reputation hasnt improved wherew should i go?

It's almost impossible to come back from vilified, especially inside their time requirement.

If I were you, I'd prepare for the rest of the game being like this...or just reloading.

oh no its says im shunned sorry?

If you're shunned, some facilities won't attack you on sight. I've been shunned by Powder Gangers and still had access to NCRCF, as well as Legion soldiers ignoring me on my way to Novac.

Well I haven't killed any ncr members and have helped them out but they are still neutral.