Why Did I Lose Eye Sight For A Minute?

I feel on the left side of my face about 4 days about from the distance of about 4 feet and smacked my left side of my face directly on the concrete floor of my garage. I was lucky enough only to have a slightly bloodied lip, left upper lip, and my check was mildly bruised, but not showing any real discoloration. I have been feeling a little ill, but I have an illness that has symptoms that mirror almost all of the symptoms of a concussion. It has been 4 days, should I go into the ER? Is there even anything they could do at this point. I am not feeling any more confused than normal and my memory is about normal, but I did have a weird issue this morning when it was still dark outside and I woke up and found that I had lost about 80% of my sight in my left eye to a black void...it was scary, but thankfully came back within a minute or so. Worried about potential concussion, should I go in to the ER?