Shifting into park or reverse!!

I was on my way home one day and when i got into my car and went to shift into drive, from park, it seemed a little hard to shift, but not too bad..the next day, i tried to put the car in park, and it wouldn't go..without alot of force...so i put the car in neutral and put the parking break on..now, i can't shift into park, or reverse so i have no reverse..i've heard of alot of people having these problems and they said i needed to tighten a connection, but i dont know where, if anyone can help me, please respond.