Do you have a registered dietician you can go to who is supportive of a vegetarian diet? We found one that our insurance completely covers. She's really great. She suggested probiotics and vegetarian dha for my daughter. I wonder if those might be helpful to you?
Have you tried keeping a food / symptom journal?
I don't think you have to add meat back into your diet to feel better.
What is in meat that you would be missing?
You are still eating eggs and dairy, so getting non-plant based foods that way.
Are you eating more of those things or about the same?
I was wondering, too, if you eat soy. What types of fats are you eating? Do you eat mostly a whole foods diet?
I became vegan when my 3rd child was 6 months old, . . . so it'll be 13 years in about 3 months. Don't give up hope! I think you can find the solution to this to help you feel better without needing to add animal flesh back into your diet.