Help!!!!! I get faint during sex!

So ladies please please i have a problem i’ve looked about everywhere and asked so many questions and i’ve got no answers so if u have any advice at all please share!!

When i get fingered or have sex it feels great but i get very dizzy and light headed and have to stop, i’ve no idea what’s wrong with me and i just want to be able to have sex without worrying if i’m gonna faint!

Help a gal out?! xx