So whenever I go over a bump the rear end makes screeching sound, and it feels like the suspension is getting loose? I guess would be the best way to describe it, does not hug the road like I would like it too.

What could be the cause of this sound?

Also, if I were wanting to do the suspesnsion myself how difficult would it be?

Thanks in advance

 

Crawl under there and look around. (With the car properly supported, of course, NOT with just the jack.) Look for broken or disconnected parts.
Chances are a visual inspection will turn up something. Grab each suspension member and give it a tug if you don't see something obvious. If anything feels loose or floppy, that's a problem. Could be more than one thing.
Invest in a service manual, like Haynes or a factory service manual. Read through the repair procedure and decide for yourself whether you and your toolbox are up to the task.
Come back and tell us how it went.