Side effects from scalp acupuncture

A few decades ago when the needles were reusable and had to be sanitised properly in autoclave etc, they could break due to the metal being so worn out. However, today the chances of a needle breaking are very very very slim.
The reason you might have felt that way was because the treatment stimulation could’ve been to strong for you or the practitioner did not choose the right points for you. Next time you go there, mention to them the way the last treatment made you feel and they will be able to adjust their prescription for you.
Otherwise try finding another acupuncturist if you wish to continue with treatments.
I’d also like to add that all acupuncturists have a different approach in their practices. One could use your head to treat a cervical issue, another your arms/legs and another your stomach. It’s up to you to find an acupuncturists that suits you.

Are you certain they are side effects of the acupuncture? You went in with cervical disc problems which can cause all of the issues you are describing, so I’m assuming you had some of these previously - headaches, particularly? Some muscle aches following the first 1-3 appointments are possible as the treatments loosen muscle tension in the area, etc. But, again, they are common with cervical disc issues as well.

Now the dizziness can happen from a certain posture with cervical disc issues or it can happen with improper or excessive treatment. You don’t mention if you had any of these symptoms before the treatment if even occasionally. This wouldn’t last so it’s not a huge concern, but if your acupuncturist only needled your scalp and didn’t use any other points I would find another acupuncturist.

None of this, however, was because you “moved a little bit” during the treatment - in theory you could get up and run around and not cause any problems with 90% of the acupuncture points when they are properly needled.

Scalp acupuncture is a legitimate style and technique so there is nothing inherently wrong with only using points on the scalp. However it is possible that the use of that technique was not the best choice for your particular condition(s). It is actually fairly common to have some nausea, dizziness and even headache for a short while after your first acupuncture treatment however for it to last days is really uncommon. If the treatment put you out of balance you might benefit from getting another treatment rather than waiting for the symptoms to go away on their own.