My campaign progress has just...gone

So I went on Halo 4 today and was going to replay the midnight mission but when I went to select what mission to pick all my progress was lost. Only the prologue was available to select and I don’t know why, all of the other missions had gone, why is this and how can I get them back? Do I have to play through the whole game again? I was only 4 missions off of completing the game legendary solo so will I have to start the whole thing over again?

Looks like it if your stuck MSG me .We can do it all in about 3 to 4 hrs on legendary