Hi...it can be GERD, u do not have to have heart burn to have it and not eating will only make it worse as ur body will produce acids to break down the food and when there is no food to break down u will notice the pains more.
Also if u r bloating as I am surmising from ur gas pains description, then it can be also affecting ur vagus nerve,....and yes it is wise to rule out ne heart issues so do look to family medical history to help understand what this may be....but eat, try 5 to 6 smaller meals to help get something in u and use up that excess acid.
Anxiety and stress will trigger this more, so do try to relax....and exercise, move more as I know it is hard now, but slowly build up as it will help u feel better. Smoking can affect how u feel...and even if u quit could still play a role in all of this.....And a bad diet can also be a part of this...eat healthy....and like I said try to relax, find a hobby, like painting or crocheting....
U may want to visit the GERD forum here on MedHelp for other tips and info.
http://www.medhelp.org/forums/show/333?camp=msc