No one can diagnose you..not even yourself. Only by going through some GI tests and consulting with a GI specialist will you be able to exclude all other causes, and come up with a diagnosis of IBS.
There are many things that can cause diarrhea..not just IBS. Stress, diet, bacteria imbalance, hormones, etc. etc....those are only a few possible causes.
The anti-anxiety meds...some can actually help with IBS symptoms..as can some antidepressants. Not because the symptoms are in your head, but because of the central nervous system being involved. There are many more receptors in our guts than in our brains..so some medications can make quite an impact on our guts.
It sounds like you have things pretty well under control at this point. If your symptoms return, worsen or change, then call and make an appt. and find out what might be going on.
A healthy diet, less stress, regular exercise and keeping a food journal for a few weeks could possibly help too. In the food journal you'd log EVERYTHING you eat and drink...and if you notice symptoms returning when certain items are ingested, make note of that, and then exclude that item from your diet for awhile.
Also remember that some OTC and healthstore items can affect your GI, so keep track of what you're taking and be very careful about adding new things in..only add one thing at a time and give it several days to see if there is a reaction or not. Some 'health' or 'natural' products/regimens can actually cause a response you may not want..so be a wise consumer.
IBS is not death sentence..but it can be a very major disturbance in your life. The thing you would want to do if diagnosed is realice that you learn to live with IBS, not let IBS live your life. That means being very proactive...and very patient. It is a very, very rare case where a person starts a medication/supplement and it changes the course of the condition. It's very trial and error, and requires a person to realize that there is no easy fix or quick cure..there is none. But some medications/supplements can help manage the symptoms to the point that you can live your life very well.
I've had IBS for 25 years..and I still have my bad days...but my life is now more 'normal' than it was 10 years ago.
So don't let yourself get anxious by trying to diagnose yourself (although the great majority of us have done the same thing). All it does is cause you to worry about things that may have nothing to do with you at all.