The state of Massachusetts has set up a $1.8-million fund for AIDS research and to help victims and their families, Gov. Michael S. Dukakis said. "I don't want to overpromise," Dukakis said. "It's clear we're dealing here with a very, very difficult disease, and it's not going to be conquered overnight." About $1.3 million of the money will be used for research on acquired immune deficiency syndrome at facilities such as the Massachusetts General Hospital, while $500,000 will be spent on helping victims and families.