Advice on breastfeeding with low supply

I need some advice. I have IGT so I know I will never even make close to enough milk for my baby so I have to supplement with formula all the time. My question is, I have been nursing her and then giving her a formula bottle after every feeding and I’m wondering if it’s worth it? It’s hard keeping up with nursing and pumping and washing bottles. I also have a 14 month old and a 4 year old. I probably make maybe 2 oz a day or so. Would you continue with nursing or just use all formula?