Hi!
Congratulations on the weight loss! It feels so good to make progress right, great job! I find exercise helps me keep my anxiety in check too, works wonders for me.
If you have hypogcemia you can go get checked for it very quickly but usually you would have symptoms of it about 30 minutes to an 1.5 hours after eating. You would get dizzy and feel wonky very shortly after eating.
Sometimes extreme dieting and exercise can make the body tired, I wouldn't worry about it too much. Obviously the body is going to be tired from the new and beneficial lifestyle.
Anxiety is a trickster, I suggest just rack it up to good old fashioned exercise and being a bit tired. Try to get some sleep too, staying up late worry about hypoglycemia isn't worth it. Even if you have hypoglycemia it can be managed well and treated. It's not like you're going to pass out and die from dizziness even though it feels that way it's highly unlikely to happen.
If you really were convinced you had a health problem you should see your doctor tomorrow, but you've got an appointment for 2 weeks later. Something tells me you're OK with waiting for two weeks, so its probably your anxiety speaking.
Ignore, defy and challenge the anxiety! One way I do this when I am dizzy is shake my head around or spin around, the feeling of actually being dizzy is much different than anxiety dizzy. Try it and prove to yourself one way or another if is really anxiety or not!