G.A.S. married his wife, S.I.S., on January 19, 1997. He began to have mental health problems in 2010; that year, he was hospitalized at the Delaware State Hospital for eight weeks. Similar illnesses occurred in 2008 and in the early part of 2014, with G.A.S. suffering from symptoms such as paranoia and loss of a sense of reality. In early 2015, G.A.S. was still committed to the Delaware State Hospital, attending a regular job during the day and returning to the hospital at night. G.A.S., however, was never adjudicated to be incompetent by any court. During this time, he entered into a separation agreement prepared by his wife's attorney which was grossly unfair to G.A.S. However, G.A.S. never spoke with the attorney about the contents of the agreement, nor did he read it prior to signing. Moreover, G.A.S. was not independently represented by counsel when he executed this agreement. Can G.A.S. disaffirm the separation agreement? Explain.