Need some help getting my leaking pool fixed

Hey there,

my self made swimming pool is losing constantly water. It hast some cracks in the wall as well. Tried to fix its several times but without success. I’m looking for a cheap and easy way to achieve this. I asked a professional what it would cost for him to do that and he said 14k. That is absolutely ridiculous. Does somebody know this: Is there some sort of plastic foil or something that is reeeeeaaally stretchy and water proof to cover the hole inside of the pool? What else can you guys think of as an easy and cheap alternative? Thanks in advance. Really hope to get some good tips here.