Advice, Suggestions?

I went to an interview about an hour away from my home. Met with the hiring manager.

He appeared to be pleased with my experience and qualifications, the interview went well. He said a woman would be calling me the next day. I was going to be hired on for the night shift in charge of a unit.

Well, days passed, no call from the woman. I called her. No response. Emailed her.

She responded with a voice mail assuring me she is putting together an offer. Said she would be calling.

That was four days ago. No call or email.

Today I called her again and emailed her.

She responded with an email that she had sent (emailed) an offer letter to me.

Checked, rechecked, no other email from her.

Emailed that I had not received it, would she please resend.

No response.

I never have encountered anything this crazy, not sure what to do.

If they chose another candidate, that's fine, I'll move on. Not a problem, (though he told me I was hired the day of the interview.)

If the hiring manager has decided I would be good for the position, and this woman doesnt know how to follow up, not sure what is most efficient thing to do.

Ive called the hiring manager (cant reach him so far.)

I guess I could physically drive an hour an go try to find the woman or the manager. I'd hate to get blown off after dressing up/long drive- Ive already invested a lot of energy and time the last two weeks.

I hate to just walk away, it might be a great opportunity (old hospital/new management, all new staff, might be exciting.)

Any suggestions?