ive seen some videos on youtube of people complaining about theyr floyd rose's bar being loose to where they can move it when its inside of the bridge and its completely tightened.

well mine does that but now it also cant lock in place at all. i tighten it as much as possible but it still rotates and hangs down. so if i tighten it when im sitting down it just falls and rests against my leg instead of staying in place

this is annoying as hell when im playing something like the crazy train solo where i have to tap and then use the bar right after and i cant get to the bar because its hanging.

anybody know how to fix this or do i just have to buy a new bar? \

if i pull up the locking part of the bar when i can see a piece of plastic that keeps the screwy thing from falling off and its cracked and a little bit of it is missing would this have something to do with it?
Teflon... you can find it at home depot for like $.50

What type of bridge do you have?
"Experience is not what happens to you. It is what you do with what happens to you." - Aldous Huxley
If the plastic bushing is cracked, then that could definitely result in a loose bar. See if you can find a replacement bushing for it before you do anything else.
"Maybe this world is another planet's hell?" - Aldous Huxley
Open up the back plate of the guitar where the springs to the Floyd Rose are. Then look for a small shaft in the lower right corner that has a space for an Allen wrench. Find a fitting allen wrench and turn the shaft to the right, this will tighten the shaft to the base of your Floyd Rose. Then you can screw your tremolo arm in place again and you should be able to move the arm to wherever you want and it will stay there.

If you want to make double sure that it tightens, hold the screw part where you put on the bar from that side while you tighten it.

Let me know if this helps.