Do I need a new fuel tank?

So few of years ago I replaced the pump and found the sending unit in pieces. I put it back together and it worked fine for next couple of years.

Last year the gauge went off the scale again, so I dropped the tank and fixed the sending unit again.

Few months ago the gauge went ballistic and at that point I just ordered new sending unit.

Today I went to install the new one and found the old one slightly split (you know the plastic piece that is attached to the metal one and it just snaps in). But then, WTF?! There is a large chunk of sheetmetal, formed like it belongs in the tank to serve some purpose, but it's loose. I just moved it around the tank with my fingers.

So I figure that whatever it is, it's not doing what it's supposed do anymore, but instead it keeps knocking into the sending unit and messing it up. I don't see how it can be fixed without splitting the tank which at that point is not even worth it anymore.

So should I just get a new tank or there is more to it? Thanks in advance and sorry for long read.

Thanks guys! I thought it was something along those lines, just needed clarification as to what the hell got knocked loose and what purpose did it serve before it broke. You made it crystal clear.