Well, you have classic symptoms of gastroparesis (GP) and it’s definitely affecting your quality of life. Your most potent tool to use to minimize or even stall progression is to get your blood glucose levels as close to normal as is reasonable for you.
With my GP diagnosis in 2012, I radically changed my diabetes care for the better. I cut carbs, lost weight, started daily exercise and closely tracked my diabetes data. I feel it’s had a good effect on my GP as it has not advanced at all. It may even be a bit better. I’ve heard reversing GP symptoms is very slow, if possible. My overall health is better, too. I feel alert and energetic and my moods are stable.
Sorry you’re having trouble getting a proper diagnosis but that shouldn’t stop you from making changes now if you’d like.