Severe pain

Going on 48 hours of random sharp pain in the center of my upper abdomen just below my sternum. I can’t find a specific cause. The pain comes in randomized waves and is so intense it forces me to tense up, grab my stomach, and become ready eyed. My stool has looked relatively dark the last two times I went, and has had a good amount of mucous accompanied with it. This AM when I woke up, I went to the bathroom thinking I needed to have a BM and only saw yellow/white thick mucous blobs in the toilet.

What would you do? What could help me? Someone please give me some advice. I’m in unbearable pain with these stabbing waves.