Loving that immense mom guilt

So I’m 31 weeks and was just diagnosed with GD.. my 1 hour numbers were super elevated (above 200) so they went ahead and referred me to perinatal so that we could manage it.. I feel insanely guilty about it even though I know it’s not really my fault, women of all sizes and diets can get GD.. I just feel bad because I’ve been working out all pregnancy, and my eating has been mediocre but not bad by any means and I still got GD.. I worry about the diet controlled aspect because I really don’t eat very much already, and all of the diet suggestions have me eating what seems like a ton of food.. other GD moms, what did you do? Also if you had to take insulin was it an injection? I’m just worried and I feel guilty because my old OB treated me like dirt when I got pregnant because I’m overweight..