Can't go into reverse

After a long journey from middlesbrough to oxford I could not put my car into reverse to park it. When I tried, it moved slightly but it wouldn't go any further, almost like the handbreak was on. It was also making a sort of cranking/straining noise, as if I were to try push it any further something would snap. After leaving it for two days it worked fine again and I used it on the short journey to and from work all week. On saturday after a 40min journey the problem occured again. I have no idea what it could be as its my first car and I don't know much about them. Does anyone have any idea before I take it to the garage? Im so worried its gonna cost a fortune! :o(