Strange, everyone seems to be responding to a post by natalac which I don't see.
Anyway, here is my two cents. I'm not going to bother responding to the "you must eat fish" or "only vegetarians are healthy" comments, because I think they're judgemental. How we eat is a matter of personal choice, and can change a lot over the course of a life. I have been a vegetarian for 9 years and am happy with that choice; I also was one for a couple years in my 20s. However, I'm 62 now, so you do the math.
When I was diagnosed 3 years ago I decided I didn't need to change my diet because "I ate healthy" (more judgements). I did, just not for a diabetic, because I ate a lot of pasta, rice, and cereal. When I recognized this I said that my health is most important to me and if I have to go back to eating meat, or at least fish and chicken, I would. I've found I didn't need to do that, but it has been and continues to be much more work to eat as a vegetarian while reducing my carbs. I'm not low carb, but stay just under 100 a day. I am able to do this and eat nutritious and tasty foods because I live near an amazing market where I can find any ingredient I can imagine, I am semi-retired and have lots of time, and I love to cook.
My questions to you would be why you are eating vegetarian. If I'm interpreting your post correctly, you started doing it after your diabetes diagnosis because you thought it would help control your diabetes and you would lose weight. Congratulations on your weight loss. I don't want to minimize that achievement, but people generally are able to have an initial significant weight loss on pretty much any diet because they are reducing intake and perhaps also increasing exercise. Now you feel you are at a plateau. I agree with what bsc said so clearly: high carb is not good for diabetes, and not for weight loss either. I differ from many in that I do believe in limiting fat intake, but a carb is a carb and pastas and cereal won't help you at all. So unless I'm missing something, and you have other reasons for a vegetarian diet (and are willing to do the work to make it more diabetes friendly), I would suggest you eat what you prefer in terms of protein, and work on reducing the carbs by replacing the pasta with healthy vegies and the cereal with eggs in the morning when we are most carb sensitive.
Ok, it was more than 2 cents!