Yea, "holds up the main" is kinda confusing. Clearly the mast did not go overboard but there are many other parts that "hold up the main"
Nautical terms can be daunting and most on this forum understand that. Can you give us a better description of the part? As a start the top of the mast is called the mast head, the bottom is socketed in the tabernacle and called the base, the "rope" that you pull on that raises the main (or any other sail for that matter) is the halyard. The corners of a sail are the "head" at the top, the "tack" which is attached at the mast at the bottom (or for a foresail (sail ahead of the mast) at the bottom of the cable that the runs from the mast to the bow (the pointy end of the boat at the front ;-) ) and the "clew" is the corner that is at the aft (back of boat) end of the boom.
The learning curve is steep but not that high so keep the faith and we will talk you off the cliff.