iphone wont play videos

Hi everyone,

suddenly today my phone refuses to play videos. When I get one sent to me (or if I send to people and click it) I open the video but it’s black. I can see the video strip at the bottom but I can’t fast forward through it to make the video move or play.

I also can’t play videos in my camera roll either. If I send them to WhatsApp they work, if I restart my phone it works for about 1-2 minutes and then stops working again unless I restart.

can anyone shed light on this? The searches I’ve done show very different video playing issues but nothing like this.