welcome to the forum. I’m also vegetarian, but like you was eating a less than stellar diet, and I was obese on diagnosis.
I’ve gone nearly all plant based now, with an occasional Greek yogurt. Beans and lentils are a main-stay of my diet. Low-glycemic/ high fiber does wonders for me. You might enjoy reading about Dr. Furhman’s plan. It’s a cheap kindle book. Plant based, lots of beans/legumes, vegetables, nuts/seeds. It’s the way I eat now daily. BMI is now holding around 22, plenty of exercise and a healthy diet. A1c’s have all been high 4 or low 5% since adopting my new diet.