Gestational diabetes at 37 weeks

so it seems like I have developed gestational diabetes in my last trimester.i passed my 3 hour test and then at my last appointment I was measuring 40 weeks at 36 so had to get an ultrasound which did show extra fluid. so now I'm testing my blood sugar 4 times a day and I'm noticing unless.im super strict it spikes. I don't eat junk food or sweets but it seems like when I eat vegetarian meals it spikes. I'm definitely learning how to control it with my diet but it's been really hard ....feeling hungry and nervous and emotional. any advise on snacks or recipes to try . I know I need to control this.