I've been having chest pain for a couple of days now, and it's pretty constant, especially when I'm just sitting or lying down. Plus, sometimes I get this pain in my shoulder and neck, and even occasionally a stomach ache. I'm 20, I don't smoke or drink, and I'm not overweight. Could this be something serious like a heart attack or angina? I'm kinda worried and not sure what to do.

Based on your symptoms and age, it is less likely to be a heart attack or angina. However, chest pain should never be ignored. It is important to rule out any serious conditions. You may be experiencing musculoskeletal pain or acid reflux. I recommend taking over-the-counter antacids like Tums for stomach ache and trying ibuprofen for pain relief. If the symptoms persist or worsen, please consult a healthcare professional for further evaluation and management.