broken game help?

[X360A Sam]

i was playing this last night with a couple of friends ad everything was the perfect i liked the game alot infact but i went to bed and loaded it up the next day and my person can't move properly i keep bumping into invisible walls and it takes me ages to get anywhere and its become unplayable i have even tried starting again and the same glitch im going to call it keep's happening is there anything i can do.