Feeling discouraged

I was diagnosed with prediabetes last year, my A1C was 5.7 then. Now I just got my new results and it went up to 5.8. Not a huge change but it's still discouraging to me. I have a follow up appointment in 4 months. I was so sure my A1C would be better. I changed my diet from a plant based diet to eating chicken for more protein, cut out sugars and carbs almost entirely. But I guess it's not enough and I need to be stricter. Diabetes runs in my family and I am 5'2'' and only weigh 100lbs now (110 last year). I don't want to lose any more weight. It's hard to find a balance for me between eating enough food and not overdoing it in exercises so that I loose even more weight. Maybe I should stick to walking after meals instead of doing strenuous exercise? I am getting annoyed with people telling me I should eat a burger and getting looks from people at work questioning why I'd rather take stairs and go for walks during my lunch break because "I don't need it". I understand this is the complete opposite problem of most diabetes and pre-diabetics but I just had to get this off my chest.