the IBS might just be an anxiety symptom, the first thing that messes up in anxiety is your stomach so I don't think you have IBS but rather high anxiety, I suggest going to the doctor and being referred to CBT. or if not that being put on anxiety medication. what you said about feeling ill needing the loo and panicking sounds like a panic attack.
when you feel the panic coming on, deep breathing is the key, drop everything else go out of the room or where ever you are into somewhere quiet where you can sit and concentrate and just concentrate on breathing, pretend there is a candle that you want to just make flicker but not blow it out and take deep breaths in and blow out slowly keep doing that and stay focused on that, if you start to panic again tell yourself that its just a panic attack nothing to worry about it cant hurt you and if you keep breathing deeply you will start to feel better
I know its scary but everything you feel at that time, hyperventilation, sweating, trembling, upset stomach everything is just a panic attack and it is something you can control and stop.