piercing pain in stomach

Again, without the typical tests I have been diagnosed with a peptic ulcer.....I think it must be that...but it's the pain that I am questioning.....I suffer with chronic migraines and now the abdominal pain and fatigue....had gall bladder surgery last July.  Since that time, this pain I feel in my stomach starts from the front, seems to move upward and to the back with severe pain and then there will be a piercing as if a knife is cutting through from the back to the front.  I take nexium daily....and have OTC zantac that I take on the occasional extra attacks...the pain is so severe that I will cry on the onset....and I will ball my head off it hurts so badly....as soon as the zantac begins to coat the stomach it settles down....is this really an ulcer?  I have never heard of people saying their acid reflux or ulcer is much more than just a burning....what I feel is EXTREME pain that seems to move...I don't know what would happen if the zantac didn't fix the problem immediately....and today I had such an attack and I took an extra Nexium and 2 zantacs 75...I could feel the pain since yesterday building up and it calmed down but continued for several hours after that....the normal attacks only last a few minutes.....this one today, really has me up set.  Any suggestions?