I've got this book to help me keep track of the carbs in things:
http://www.amazon.com/CalorieKing-Ca...3267619&sr=8-1
According to the book, a 7 oz baked potato is 42 carbs on its own. 7 oz, is not a very big baked potato. I'm borrowing a food scale and measuring everything. To give you an example, the apple I brought to work for a snack today about 7 oz (I weighed it this morning and I probably won't eat the whole thing), so your potato was likely bigger than that. My dinner carb allotment is 56-65 carbs, so you might have been in that range regardless, but you didn't have protein at the same time. The protein helps with the absorption of the glucose (or so I'm told). Also, that range is based on my pre-pregnancy weight and age, so who knows what it is for you.
I will admit that I never get up as far as the range I've been given for dinner carbs though. I'm usually in the 40s. Last night I had some white meat roasted chicken, kale, 2/3 cup of quinoa, which is 36 carbs, and 1/2 cup of sugar-free chocolate pudding made with whole milk, which is 13 carbs, for a total of 49 carbs for my dinner. FTR, my dietician said not to even bother trying to count carbs in green leafy veggies, even though they do have a minimal amount, so I didn't even look up the kale. It was actually a lot of food and I felt really full, but my blood sugar was just 107 (though I did do the stairs after dinner).
I have a much harder time in the mornings for the fasting level and the after breakfast test. I've never had a fasting level under 90 in the week I've been doing this. So, your 115 level is about where I am every day. I think if I go on meds, it will be because of that. The dietician told me that the main driver of the fasting level is just your hormones, and while eating the before bed snack helps, it doesn't necessarily help enough.
I'm sure this must be much harder for you as a vegetarian than it is for me. Beans are good though. 1/2 a cup of canned pinto beans are just 19 carbs, and they've got a lot of fiber and protein in them. I can't seem to find tofu in that book, so I don't know how much that is without looking at a package. And, I totally get the difficulty of fitting in the exercise. My DH is here, and my DS is older than your DD anyway, so it's not as big of a deal for me to do the stairs in my house for a little while after dinner. And so far I haven't swelled up at all. I'm worried about getting the exercise in as I get closer to my due date. Just over 9 weeks to go.