Ron I just wanted to say that I've been through something very similar on two separate occasions. The first time I had a bullying boss, procedures weren't followed and I ended up very nearly having a nervous break down before I got another job and left. The second time my boss was supportive and procedures were followed to the letter and whilst still stressful it was completely different.
There was no official action taken against me the first time because HR processes weren't followed. And because the allegation was untrue. I wish I'd made a grievance against my boss (what she did to me was sustained and serious bullying). She did reduce my appraisal grade but by that point I had given up and just wanted to get out so didn't even speak in the meeting. Not that she noticed It is a big regret of mine that I didn't fight harder, but at the time I was young and didn't know that some of the things she was doing weren't just immoral but ilegal.
The second time I had been sent in to tackle a problem team and one member of staff made serious but spurious allegations against me. Process was followed to the letter, grievance made by the member of staff, fully investigated (including interviewing every member of my staff) and the outcome was that there was no evidence that any of the allegations were true. In fact, the investigator found the "victim" was in fact guilty of most, if not all, the allegations . That time I was older, wiser, knew the HR processes inside out and back to front, my legal position and had the support of my manager and union. Yes, it was still stressful but it was bareable and I am glad I stuck it out. I found out later that at the appeal she had complained that she didn't like "the way she asks me to do things". When asked what it was she didn't like she had been unable to say, even when prompted "was it the tone used? the language? did she stand too close to you when she said it?"... turned out she just didn't like being asked to do anything!
What I wanted to say, is that I absolutely understand how you feel betrayed and bewildered - but you will get through this and it will get better. You have some good advice on here from Ribenaberry which you should take. Always ask for specific examples and do not resign. CAT me if you want some extra support from some one who's been there.