Given your age (I'm assuming you were the usual age when you took your AS levels) the most obvious route is to redo A levels. Most foundation courses won't consider you without a full level 3 qualification.
An alternative would be to do an Access to H.E. course (Engineering or Science pathway) which you may have to follow up with a foundation year. I got into university following an Access course, but it limits your options, as not all universities will accept it for a physics degree.