Exhausted after eating

Im at 32 weeks, and in the last week I've suddenly felt extra exhausted. It happens every time I eat, no matter what I eat - 20 minutes later I'm falling asleep. It's like my body has to dedicate so much energy to digesting the food, it can't do anything else. It's becoming very problematic as I'm still working full time (speech therapy), and I see patients all day, so falling asleep at my desk every day after lunch is not the best way to give my patients good care. Plus my drive to work is 45 min, so if i eat breakfast, the tired crash arrives as im driving - not good. It's gotten to a point where I'm delaying eating because I know I'll crash afterwards, which of course is a terribly unhealthy strategy.

I've been trying to see if what I eat makes a difference, but I seem to react to all foods mostly the same way. Carbs and processed sugars are a bit worse, so I'm avoiding those. Trying to stick to high protein meals. But it is still happening.

I'm seeing my doctor on Wednesday, and will obviously be talking with her about this in detail to get a professional recommendation. Just curious if anyone here has had a similar experience, or had ideas to keep up my energy for the next couple days until I talk with the doctor