New to Forum, first episode ever

Hello all, 

I am a 22 year old male, two nights ago as i was getting ready for bed when i felt a sense of anxiety come over me, while it was happening I thought it might be a panic attack, but i was not nervous or anxious about anything. It felt like something needed to change so after finding that i did not need to throw up i tried to will  myself to relax, controlled breathing focused thoughts, this momentarily helped and i thought i was better, so i stood up and tried to make it to my room. I fell down in the hallway while still fully conscious and i saw my body convulse, or rather it looked like i was trying to roll from side to side. I can't honestly say how long it lasted i think it was no more than ten to fifteen seconds. This is the first time anything like this has happened to me, including the sense of anxiety out of no where

Additional possibly irrelevant, I have been having stomach issues for over a year now, diagnosed as IBS after every negative medical test ruled everything else out. On top of this i have constant muscle twitching in both calves, which has gotten more active in the past quarter year, diagnosed as benign fasciculations, two years ago.     

Any information of similar experiences and what you did about it would be helpful, thank you