Any over-the-counter medication for Bartholin's cyst? I have no insurance and no money to visit doctors that often : (thank you so much

Not really. You can try a sitz bath to see if it allows the cyst to drain. IF you go to a federally qualified health care facility using this website, you can be seen and usually get cheap care based on your income. This is called a sliding scale.
Sitz baths. Take a shallow pan, fill it with some warm water and put just a little Epsom salt in it. Then, soak the perineum (outer vulvar/vaginal area), presumably involving the area of the Bartholin's cyst, in the solution for about 5 minutes daily (roughly for about a week). This should help a little. Good luck!