Challenging question! Especially in light of the recent rise in cost of healthy food and most of the inexpensive diabetes medication choices can cause weight gain.
Recommend finding Good Food Boxes, community gardens, community kitchens, walking programs, free PA programs
Metformin is relatively inexpensive and neutral regarding weight.
Use compassionate programs that are available for antihyperglycemic agents
Sometimes community clubs (Lion’s club for eg) will help support if there is a need