According to the Real Estate Law that is taught in Massachusetts a consideration which is usually a money deposit has to be physically accepted with proof ( usually a signature) by the seller in order for an offer to be legally accepted.
Do not fret over this one property as another great one will come along soon.
Jack Conway Realtor
855 East Washington St.
North Attleboro, MA 02760
The verbal acceptance is not binding.
It would be a courtesy for the seller to allow you to stay in the deal with an increased bid. Let your agent fight for you.