Gestational Diabetes ... 😢

I was diagnosed a week ago after my midwife at my 28week appt noticed I was measuring 2cm bigger than dates. I saw my diabetes nurse on Tuesday and have been given until Friday to get my sugar levels under control via diet as she sees it as urgent to get them sorted or she will be prescribing me metformin and possibly insulin. Trouble is, this is my first pregnancy, and pre pregnancy I am so healthy even colds go out of their way to avoid me. This is a major shock. Yesterday was my first full day of sugar monitoring and my levels were too high and I was told if I have more than 3 high ones metformin is the next course of action. To top it off ... I saw my GP this week and I have a severe chest infection which is making me feel like I have the flu. I'll be 30 weeks this Saturday, so I have a long way to go and everything seems to be against me. I'm devastated and struggling to come to terms with what to do and trying to find food swaps. I'm scared to eat now and even 'normal ' meals are making my sugars high. I was starving yesterday ... I feel defeated. Please tell me I'm not the only one who felt this way. I feel guilty for feeling so upset as I know it's not my fault I have developed this but I'm frightened for my health, my babies health and my future health in any further pregnancies and when I'm older, I'm more likely to develop type 2! 
My husband bless his heart, didn't know how to console me yesterday .... I hope u guys can shed some light ... Sorry for the essay