Nervous feeling

Hi again....I've written once into this forum but am inclined to write again because of some symptoms I feel is related to IBS but am not sure and I guess I'm looking for clarification.  I have IBS, Hashimoto diesease (which is thyroid) and I have RLS (restless leg syndrome) My thyroid problem is what brought on my IBS I think but at the same time I was going through a bad relationship when this started.  I have had RLS tho since I was young.  I take thyroid medication, I take Buscopan for my IBS only when symptoms are present and I take nothing for my RLS ...the only thing that helps my RLS is if someone massages my calve muscles and the harder the better.  So that is some back ground...what I don't understand is the attacks I get once in awhile which seems to be of the nervous side..last night everything was going as normal and then all of a sudden something come over my body and all I can explain is it was like a nervous feeling, I felt weak..a little warm and my body felt sort of nervous inside...this is so hard to explain the feeling, there was no pain, no heart beating fast, no sick stomach, just this kind of nervous feeling throught out my body and I could feel it in my legs. This lasted for about 2 hours, during this time I had alot of gas and went to the bathroom twice but my bowel movements were formed.  I took a buscopan also cause I heard that IBS is tied in with the nervous system, I also at times get a dry feeling in my mouth before this happens.  I don't like the nervous feeling that comes on and am wondering if anyone else gets this with IBS or am I looking at a whole new medical issue?