Hello

It is my first day of 'the time of the month' and i dont usually use tampons unless on holiday or i am going swimming. I normally feel faint and weak after i put them in but today when i went to get my swimming stuff my vision was a blur and my body was so uncontrollably weak and i collapsed and fainting for about half a minute i luckily collapsed on the bed but when i went to carry on i was shaking and sweating and my period pains were like massive stabbing pains and i felt like i was going to vomit at any minute. my mum got me a hot water bottle to put on my tummy and it eased the pain slightly but had to stay in bed for half the day because of how weak and how much in pain i was. Do you know what the problem could be? shall i just not use tampons and not go swimming when i am on?