Sue, glad you joined us but sorry this is happening to you.
My husband had foot drop also, but it was a little complicated. He did trip and fall and injure a nerve in February. The nerve injury itself can cause drop foot. However, it was not until April 2nd that we noticed he actually HAD drop foot, and so the trip to diagnosis began. To this day, they are not 100% sure if the drop foot was caused by injury or the other way around, because the drop foot at least partially recovered, he can almost fully raise those toes up now.
It is as likely as not though that a leg/ankle weakness, if not a full drop foor was still the cause of the trip and fall. My husband has been one not only very fit but graceful man. I remember friends watching him get up on the roof of our garage just in the summer of 2015 and saying " Wow! Just like a cat! Are you sure he is 65?" So the fall itself in his case was a warning sign. In my case, it would be just another day as I clumsy for sure.
He was diagnosed June 30th. We were already getting towards an ALS diagnosis when he developed weakness also in his left hand you could see on June 15th which sealed the Dx even before the Doctor declared it in my mind.
Heavy cramping in his legs with big physical activity starting in Fall of 2015 may have been his first symptom. Now, he uses a cane some of the time, uses a bath chair, wears leg braces and has lost a lot of dexterity in his left hand (can't type with it anymore) and has pain in both hands, sometimes severe.
I would not be surprised at all to see Brian using a walker in 3-6 months. It depends on how progression really goes.