Shock absorber or something else

I get rear end sway when I am going around an exit ramp or an on ramp. Also there doesnt seem to laot of bouncing when I hit a bump but there is alot of vibration when I am driving down the road. It actually shakes the hood. And I feel it in the steering wheel. Is this shock absorber problem or something else. I was going to change them myself but dont' want to spend the money if I dont need too. I have a 95 nissan pathfinder with 208000 miles on it, xe-v6, four wheel drive. I have had new tires mounted and balanced put on the truck very recently.