Hello Melanie and welcome
In my personal opinion you might have atonic fits
and need to get consultation from your neurologist
. Your doctor may order you CT head and EEG to get to a diagnosis. Do not worry and feel free to consult your neurologist doctor. As precautionary basis anti-epileptic drugs are the choice of treatment in your case. Other cause can be anxiety
disorder but I do not think you have this.
Hope this will help you.
Best Wishes and get well soon.