It's wonderful that you're still gaming! We have all ages here at GB, with quite a few in their 80s, same as you.
There are two bottles of antidote that it is possible to collect along the way. Did you win a game of Raven yet? (The game on the chest.)
There is a bottle on the shelf in the pier building, and also, as mentioned, one in the locked chest with the Raven/Snake game.
If you start a game of Raven and then leave your computer alone without touching either keyboard or mouse for about an hour or so, then the puzzle *should* auto-solve and the antidote will appear in your inventory.
However, several members have reported this skip feature not working for them. But it's worth a try.
Otherwise, keep starting a new game of Raven until you find one which has many more ravens than snakes and so will be likely easier to win. The ratios do vary from game to game.
I don't have any saves for this game, unfortunately.