Concussion likely or not? -sort of long details of the past days?

You likely have a mild-moderate concussion- type 2 would be my guess. It sounds as though your brain, when you fell, struck the front portion of your skull which is why the majority of your pain is now centered toward the front despite hitting the back, left quadrant against the ground. It may also be possible that when you were in your accident, your brain hit your skull hard enough to cause a leak in brain fluid. A decrease in fluid around the brain would also explain/lend to why you're getting dizzier when you stand as well as why you're having increased nausea. To maintain food intake while minimizing nausea, try eating the B.R.A.T. diet (bananas, plain rice, applesauce, toast) for the next 2-3 days. While it might not fill you up as much, it will provide you with much needed nutrients while calming your stomach. You'll want to avoid loud noises, bright/flashing lights, and further injury to your head and neck for about a week until the symptoms begin to dissipate. Maintain the recommended dosage of an over the counter prescription pain killer such as ibuprofen/motrin or aspirin. Try not to take too much Tylenol if that's all you have as that will often upset your stomach more and potentially cause other issues. Keep up on your fluid intake by drinking lots of water but in slow, steady sips. If you don't begin to feel better or your symptoms don't improve within 5-7 days, it would be a good idea to seek medical attention. If you don't have a doctor or money is tight, you can always go to the ER and talk to a case manager or someone in billing who should be able to either set up a payment plan or use a donation-funded account to cover some or all of your costs. If you were in a crosswalk when you got hit, had police involved, and you got the person's insurance info, it might be a good idea to be seeking medical care through their insurance as part of an accident claim. Most importantly, this is why it's so crucial to wear a helmet. Granted, your supposed adrenaline rush aided in protecting you from more harm, but nothing protects better than a good helmet....even if they don't always look so "cool." Good luck to you!