I can't differentiate between OCD or the smell of vinegar, and need some guidance

I understand what you are talking about. I get that paranoia with every batch. In my case it is with fruit wines, meads, and ciders. Sometimes the mind plays tricks. If you sanitize decently you shouldn't worry to much. People are obsessed with sanitizing and much of it is overblown. People have been making beer, wine, and liquor for ages and until more modern times sanitation was sketchy at best. Up until very recently bleach was used to sanitize and now you would think bleach was born of the devil and will ruin a batch 9-out of 10 times...Which was probably an invented issue by the makers of niche sanitizers to sell more product (though brewing sanitizers are much easier, safer, and non-rinse is a tremendous selling point, and the product is well worth it).

When I am ready to bulk age a wine, I usually have my moment of paranoia. There is sometimes a slight vinegar smell, and when I take a taste there is a sharp biting aftertaste. It doesn't taste great. A lot of times though, I just pull out a bottle of red wine vinegar and have a smell and taste and immediately go, "Ahh OK, the wine is not vinegar..."

A lot of times the yeast feeding frenzy which creates the alcohol will just overpower a batch leaving you to question both your taste buds and your nose. Most of the time it just needs some time to age. The aging mellows out the bite. Since fermentation should be finished and the product racked off the yeast, all the flavors will start to come together and you will be surprised with the result. It's kind of the magical brewing process. I've had a fruit mead that I was paranoid about, and thought was horrible and a disaster after secondary fermentation, especially because honey is a somewhat expensive ingredient. I bulk aged it and after six months I was wondering about it and took a taste, and it was really good. After a year, I finally bottled it and it was the best batch I had ever made.

Just have some faith in yourself and the process, and don't start throwing things until it's fully complete!

The cider / vinegar smell is normal, it is acetaldehyde and is a normal byproduct of fermentation. But it's a temporary byproduct, the yeast will consume it to recover NAD+ from NADH after all oxygen has been gone for a while.

If I recall correctly, even acetobacter needs oxygen to actually make vinegar. So the problem is apparently oxygen more than contamination.

Make sure your fermenter is sealed properly, and that you don't get oxygen into the beer when racking. The current preferred method to prevent oxygen at racking is: don't rack at all - it doesn't help the beer unless you need to keep it in the fermenter for more than a couple months.

I your case, don't worry, but do bottle condition the beer (kegging, with artificial carbonation, would not help this). A little kick of sugar will wake up the yeast and get them to clean up the acetaldehyde.