Managing glucose and iron

Failed the glucose tolerance test by literally 0.1! I am convinced that it was impacted by my eating the day before as i was on the go and running off high sugar foods and drinks and little protein and fiber. BUT what are some ways to manage my blood sugars better? Do i have to avoid fruit smoothies? (Usually protein powder, greek yoghurt, coconut cream, berries and spinach) as this is my big craving this pregnancy so my diet consists a lot of this as well as natural fruit juice and yoghurt. Do i have to switch to diet alternatives? Obviously you're supposed to have meals consisting 1/3 each of protein carbs and veg, but does this change with gestational diabetes? And also my iron is severely low (probably becausei have a meat aversion currently) and i cannot take iron pills as i get severely constipated... anything i can do to help that either?