About Two Weeks Ago I Feel A Few Times For

about two weeks ago i feel a few times for no reason i had no indications no pain and no warnings. then i began to limp it quickly got worse i started using a crutch within four days i had to use both crutches ,, i have no problems above the waist but i barely have enough strength in my legs to stand, i can feel my muscles are tense and sore like i've been working out, my legs swell sometimes and my feet get numb and tingle, i went to the ER and saw no problems i will be seeing a family doctor this monday, my mind is spinning with all the reasons of why within two weeks i can no longer walk, i'm greatful for any insight you can give me