Where can i find my actual Coat Of Arms?

A good place to start would be Burke's "General Armory of England, Scotland, Ireland, and Wales", a reference book listing all known British and Irish arms. It so happens that the whole of the 1864 edition is available online via Google Books, at the link below. You'll see on page 71 that there are a number of similar coats belonging to different families of Bennetts, and when that happens it usually means that these families descend from the same ancestor and have adopted different versions of the arms to distinguish between them. There is one which sounds exactly like the one you describe: it's listed as being the arms of Sir Thomas Bennett, Lord Mayor of London. So you might try tracing your ancestry back to see if you can prove a link to him. (After all, it's not 100% certain that the arms on the cross-stitch was your family's; it might have been bought second-hand, or the ancestor who stitched it might have been wrong in thinking it was theirs, etc. etc.)