Kismet, I had a life-threatening C. diff. infection about 23 years ago. I ran from one doctor to the next and none even thought to test me for C. diff. One gastro told me after the fact that, "You didn't look like the typical patient with a C. diff. infection." I wound up with a toxic megacolon and was within minutes of it bursting and killing me. I had to have part of my colon removed in emergency surgery. Probably the only reason I survived was because I was in peak physical condition. Because my infection was so severe, I was automatically given vancomycin right after surgery. Vanco is reserved for patients with more severe infections or recurrent infections.
It is not uncommon for people to have recurrent infection. My symptoms returned shortly after I finished my first course of vancomycin and I was prescribed a second course, which did the trick. The literature states that people who have a relapse are more likely to have recurrences, however, I haven't had a problem since that time. The literature also talks about C. diff. spores being reactivated, but I don't know if these spores can remain in the body for three years, in your case, then somehow become reactivated.
In 23 years, I have only had to take one antibiotic for strep throat. Otherwise, I avoid them like the plague. People who have had C. diff. infections are much more likely to incur another C. diff. infection when taking antibiotics subsequently. Under no circumstances should you ever take an antibiotic unless you have contracted a bacterial infection that has been tested for and identified as such. Even the general population should heed this advice.
I also did my research for a good probiotic and decided on Culturelle for myself because it contains 100% Lactobacillus GG, which has been studied specifically for C. diff.
As far as the side effects you read about for vancomycin, yes, they are scary, but they are also scary for metronidazole (Flagyl), as they are for most antibiotics. Of course, intravenous vancomycin will be more problematic than oral vancomycin. Are you sure you read about oral vancomycin? I didn't even have the knowledge of side effects at the time of my infection, but I had no choice in the matter. It was vancomycin or my life. You may have read there are several factors that might make vancomycin more dangerous. They include an elderly person, one with compromised kidney function, whether you are on other medications, etc.
If you are that fearful of vancomycin (and I understand your fear because I refused to have a contrast MRI a couple of years ago because of the side effects of the particular contrast material; instead, I was able to identify an MRI facility that had a "fast-spin" technology that worked as well as contrast in giving a detailed image.), I'd ask your doc if you can repeat a course of Flagyl. I would also suggest you speak to as many pharmacists as you can about this. They usually know a lot more about drugs than docs.
Best wishes to you and feel better!
ETA: If/when you go on another course of antibiotics, make sure you know when you can take your probiotic during the day. I believe it has to be a certain number of hours after the antibiotic or else it negates the antibiotic.