Why are you doing this? Is there some point to knowing that her sexual episode lasted 5.5 hours instead of just "a couple of hours"?
Look; your wife has blown this off as "just sex"; nothing more, nothing less. No boyfriend/girlfriend commitment, no love, no caring about this other person. Just sexual release. Like many men would attempt to explain when they step out of a relationship and are rather flabbergasted when their partners are destroyed by what they have done.
You are torturing yourself tracing all their places they have gone to and what they have done.
Either accept that your wife has some need to seek outside sexual fulfillment and may very likely continue to do this since, it appears, she has little or no understanding of what this has done to you or move on for this marriage.
At any rate, you are, literally, driving yourself insane over this matter.
Stop wasting energy on checking out all these places and make a decision as to whether you wish to continue living with this woman or not. Now.
If you wish to continue living with her, understand you can NEVER trust her again. There is no guarantee she will not repeat this experience.
If you don't wish to spend the rest of your life waiting for the next shoe to fall, begin the process of divorce. Now.
There are many "herbal" products that claim to increase desire but frankly, the issue is often hormonal in nature and unless these can be replaced with prescription products these other claims tend to be bogus.
1. You've trained yourself for years to only orgasm with your own hand. 2. Yep, although it's likely to take quite a long time to untrain yourself after years of reaching an orgasm via your only method of being able to do so. 3. If you overly focus on all of this, your concerns are only likely to make things worse.