A piece of my tonsil it's just hanging there in my mouth, it's like a flab.
It's ok. Everybody is a little different. If you are really worried about it, an ent doctor can biopsy it for you in the clinic.
Probably a residual lymphoid tissue follicle. Advise to leave it alone.
It looks like some excess tonsillar tissue. See an ENT doctor for removal in the clinic. This should be very straightforward.