Feels like hundreds of tiny cuts inside of mouth, comes on suddenly like a breakout, lasts for a week, very painful.?
Unusual. Any bumps or lesions or swelling in your mouth? Recent infections? Recent travel? New meds? Any associated rash? As you can see lots of questions that would best be answered by starting off by seeing your primary care doctor to discuss all of this. Also keep a diary of all symptoms...When it starts, stops, etc.
Burning mouth. Syndrome? Things like canker sores will be isolated to a small area of your tongue, the side of your mouth, or the inside of the lip. Yours is one of those complaints where a picture is worth a 1000 words. You are going to have to see someone. I suggest starting with your primary care physician.