I'm suffering headaches, dizziness, anziety, eye pain and head pressure after low dose of botox. Is this normal?

BOTOX has few side effects and they are rare.  Headache is one of them.  This could then lead to dizziness and anxiety as well.  It should improve in the next few weeks.  You are not in danger of anything serious at 1 week, and you may want to see a neurologist before another botox injection.  Xeomin acts like botox and may give you the same side effects.

These
side effects should resolve within the next few weeks. However, there is no
guarantee that you will not have these side effects again next time you have a
treatment with Botox.

The symptoms you describe are real to you after what is a relatively small dose of Botox.  Since it weakens muscle, the opposing muscles become relatively stronger. This effect can be used for cosmetic benefit, but you may also feel the change in muscle tone. The Botox you were given is already absorbed by the nerves it was exposed to and will not likely progress due to the drug alone.I was involved in the original FDA studies using botox for eyelid spasms before it was a more consistent Allergan product.  At that time, we were masked between placebo and the real drug.  In all cases, the real drug effect of muscle weakening became apparent within a week or more after the injections and had a more lasting effect than the placebo.  Interestingly, the symptoms of nausea and headache were remarkably similar to both drug and placebo.Xeomin is a similar product made through a different process. The body does not "get used to" botox, but can form antibodies to the protein surrounding the actual drug. This typically reduces the effect of botox, but does not represent a danger to you. Improvements in the production process has reduced this as an issue.  I have never seen this reaction to the doses botox used for cosmetic purposes. If you choose to try botox again in the future, it would be important to carefully plan the dose and areas injected.  Allergan cannot respond whether these reactions are from the drug, or not, because they have been reported from both the drug itself and from a similar injection with saline (see package insert on Allergan's website). Therefore, you need to discuss these issues with your doctor. One simple solution would be to consider a saline injection in the same areas as a test.